In my arms (temptation)
by FrenchCaresse
Summary: Sherlock, too old at nineteen, has not managed to escape biology it seems. Sherlock is presenting. As Omega. And he has asked for Mycroft. Holmescest, angst, gender issues, daddy-kink and Alpha/Omega heat. With a sprinkling of Mystrade. Written for adults.
1. The ride home

_Hi guys!_

 _This story is... different. First off, new fandom for me so I probably twisted canon some. I couldn't resist exploring Alpha/Omega dynamics though._

 _Secondly, Mycroft took control of POV. And he is not particular coherent, especially at first. I swear, I can actually write full sentences! I completely blame Mycroft for the choppy style that takes creative licence with grammar and uses present tense._

 _Thirdly, this is a one-shot with 4 or 5 chapters. I am currently halfway through chapter 4, so I anticipate no problems posting weekly._

 _And now, the warnings. I write for **adults**. Will contain **angst** and **sex**. Also, a new one for me, __**sibling incest.** Mention of **drug use.** Finally, there is always the **consent issue** when playing with Omega heat, although Sherlock is remarkably lucid._

 _Lets dive into Mycroft's head a bit, shall we?_

* * *

Sherlock presented.

Finally.

Mycroft leans back against the plush car-seat, making the black leather creak.

Sherlock presented. Rather, Sherlock _is_ presenting.

Right now.

Mycroft's hand is clutching the umbrella handle too tight. He makes himself let go, watching the drab scenery flash by. Finds himself smoothing his thick trousers over his thigh instead.

Sherlock is presenting...

As an Omega.

...

Mycroft purses his lips, being driven back to the Holmes Estate. Of course, the parents aren't there. But Sherlock is.

Sherlock.

Sherlock, an omega.

Sherlock, an omega _in heat._

 _..._

Mycroft feigns nonchalance, wishing for a smoke. Inside, he is screaming at the driver to go _fasterfasterfaster._ He can't get there quickly enough. If Mycroft plays this right...

It is more than anticipation, this itching jittery roil inside him. It is trepidation, overwhelming and annoying. The surprise culmination of years of longing from his brother and staunch refusal by himself. Archaic conventions repeated _ad_ _nauseum_.

Siblings.

Brothers.

 _Incest._

Wrong _._

Sherlock does not believe rules apply to him. It is annoying, because it makes his behavior unpredictable. Mycroft doesn't believe in rules either. It is a deeply buried secret, but Sherlock has figured it out. It makes him insufferable. He sees Mycroft as a challenge; teenaged Sherlock grew ever more inventive in his seduction while maintaining apparent innocence.

It was maddening. Mycroft's body betrayed him every time. It still does.

His brother's long frame draped just-so on the couch, too-big pyjamas bottoms falling off sharp hip-bones; Mycroft maintained control. Barely. The soft brush of fingers against his, passing the newspaper, had Mycroft swallowing down an indecent moan. A whisper of air across his neck, pointing out something on the screen over his shoulder; Mycroft tried to remember how to breathe. Control. He clung to it desperately.

He still does.

Sherlock knew. Sherlock _still_ knows.

Brothers. _Wrong_.

Then WHY did it feel so right?

...

Mycroft licks his lips. He's too hot.

Sherlock is waiting for him.

...

Temptation. Mycroft resisted, for so long. Forever.

It had become a game to his little brother. Mycroft knew it, but he couldn't make him fucking _stop_. It had become the cruellest exercise in self-control Mycroft could have devised. Temptation. Mycroft had cultivated calm refusal like an art form, ignoring his body clamoring for relief, for more, for just a touch.

 _Torture_.

Until Mycroft didn't even know why he still held back. Eventually, he'd lashed out when it got too much. Temptation. _Too much_. Mycroft wanted to scream in anguish.

As a last resort, Mycroft had tried to force his infuriatingly arousing brother away. He'd hurt Sherlock with words and brutal truths while his own will-power crumbled between his fingers.

It had worked too, or maybe that was just life taking them down their independant paths.

 _Torture_.

The Holmes' brothers tightened the masks they wore. Locked away fragile childhood emotions and desire; hid behind cutting remarks and cold disdain. They barely saw each other. Even less, now that Sherlock had escaped heavily into drug use.

He was still tempting to Mycroft, even high and too thin. Gods it was worse, in some ways. Those big eyes, glazed and not quite focusing on Mycroft, still promising more; Sherlock was all pointy elbows and too much pale skin these days, marred by bruises and track-marks.

 _It hurt._ Chapped lips pouring out facts that were like barbs, pointy and impossible to dislodge; pure unfiltered glimpses into his brother's ripped heart.

 _It hurt_. Mycroft _hated_ to see Sherlock wasting away. Hated, _hated_ the unbidden thrill in his blood when he rescued Sherlock from yet another crack den. The sigh of relief when he found him still alive. The heady power of gathering Sherlock's uncoordinated body into his arms. Of being stronger, of feeling wiser; he was the big brother who would always be there.

Mycroft _hated_ himself for savoring the power-trip. _But he repeated the pattern anyway._ Helpless _._ Trapped. Stupid.

It always _hurt_ even more when Sherlock came down, spewing vitriol and sick, thrashing to get away. Mycroft knew he couldn't comfort Sherlock. Not how he wanted it. It was tearing him apart. Mycroft needed to bring the innocence back into Sherlock's too-cold eyes. He _hurt_ to keep his brother safe.

Torture.

Staying away, watching his brother destroy himself through the cold lense of grainy surveillance imagery.

Masks, barely held in place.

 _Hurt_ , his erection unrelieved and painful, alone in his apartment; remembering the smell of Sherlock's soft hair.

...

Mycroft had forced Sherlock into rehab three months ago.

...

Masks, slipping.

Genuine distress in Sherlock's stormy eyes. He was out of control and he knew it. _Hurt_. Mycroft had allowed himself to hug his shaking brother, held him close during the long drive to the center. Temptation, still, even if Sherlock was unwashed and too bony. Temptation, muted by the lancing _hurt_.

Triumph, when Sherlock had softened in his arms; quietly pliant and heavy over his knees. Sherlock had allowed Mycroft to massage the knots from his shoulders; to draw circles and formulas with his fingertips, inscribing words he couldn't say on his brother's too-bumpy back.

"Why?" An unasked question, screeching in the silence.

Regret.

"Make it stop." A barely heard plea, breathed into the warmth of his lap. Mycroft had needed to close his eyes, concentrating on keeping the panic at bay. Sherlock, broken.

It was going to be okay. _Hurt_. Sherlock falling apart. _Hurt_ , so strong Mycroft could taste it.

Sherlock would be all right. He had to be. A shared quiet moment in a car that drove too fast. Their first real connection in years.

Then... Masks, falling back into place.

Sherlock's viscious whisper as he left.

"I hate you, Mycroft."

 _Hurt_. God, it hurt.

It had needed to be done.

...

Sherlock had gone through with rehab, surprisingly, and Mycroft had stayed away since. Paid for everything, of course, and the miserable room his brother was currently living in too.

Well, the room he HAD BEEN staying in.

Now, he waited in his old bedroom.

For Mycroft.

...

Mycroft shifts on the hard car seat.

Sherlock, waiting.

For him.

...

Because Sherlock is presenting.

Sherlock is Omega.

Sherlock is _in heat_.

And Sherlock has asked for Mycroft.

...

Mycroft is done with _control_. Done with torturing both of them.

Mycroft is tired. He's been hurt too badly. He almost lost his brother.

...

Mycroft is Alpha. Of course he is. It had never even been a question. He doesn't use his gender much, except when strictly necessary to ensure things go his way. He never succombed to rut. He has never mated. Lovers are a liability, possible fodder for black-mail. Better to endure the occasional inconvenience of his body uselessly wanting to knot than to see years of work destroyed by a photo or two.

Control.

It is hardly difficult, after Sherlock.

...

Sherlock is Omega, unbelievably. Not Beta after all, as everyone had come to believe when he failed to present.

Sherlock, too old at nineteen, has not managed to escape biology.

The news had thrown Mycroft like a blow to the gut; so short for a life-altering message. A few terse words.

"Sherlock is presenting as Omega. He needs you."

A cellphone number no-one knew, except for a couple presidents... And Sherlock. Always Sherlock.

The message was genuine then. Mycroft's world twisted sideways. He could actually feel his walls desintegrate to shambles, gravity re-orienting itself.

Enough.

 _Mycroft, broken._

...

He had ensured the utmost privacy, as much absolute secrecy as he could under the circumstances. At least Sherlock had stayed out of public hospitals. He had picked an unlikely, but truly trustable ally. Sherlock might be Omega, but he was still intelligent.

...

Sherlock is Omega.

 _His_ Omega.

...

Mycroft leans his head back against the car-seat as the vehicle jolts on unkempt country roads. They are getting close.

Sherlock waits.

 _Sherlock is in heat._

Sweet Sherlock, his brother.

Omega.

...

* * *

 _This chapter was mainly backstory. And hanging participles and one-word sentences. The next one is more coherent. Mycroft is about to get a surprise when he reaches home!_

 _Note; If you are one of my **Ai No Kusabi** folllowers, thank you for your patience. This story invaded my head and I couldn't write proper Katze when Sherlock was taking all the space! I'll get back to you guys as soon as I can!_

 _xxx_

 _FrenchCaresse_


	2. In the kitchen

_So, an early post because I notoriously suck at holding back fully finished chapters! I am in awe of how active this fandom is, thanks to all the people who gave this fic a chance!_

 _A word on gender. In this verse, **your gender is Alpha, Beta or Omega**. As such, your sexual orientation is defined by it. A **heterosexual** is attracted to someone of **opposite gender** (example alpha-omega). A **homosexual** is attracted to the **same** __**gender**_ _(example omega-omega). etc Your physical sexual traits, male or female, has no incidence on your gender much like race doesn't in our world (example being caucasian does not impact whether you define yourself as a man or woman)._

 _Let's get this story moving!_

* * *

Mycroft smells him as soon as the car door opens.

Sherlock.

The driver smells him too. The man stands tall in his black suit, as competent a bodyguard as he is a driver. He is Alpha.

He is taller than Mycroft. It is annoying.

The man's nostrils flare, _once, twice._

He unconsciously savors the aroma, sharp spice and maple sugar. Enticing.

 _Omega_.

Heat.

Sherlock.

The pheromones are faint, in the windy garden, but they are unmistakeable.

Sherlock waits.

...

The driver is Alpha. Mycroft can't stand having him so close to Sherlock, not like this.

He cordially sends the man away.

Mycroft is Alpha; he is the man's boss.

Mycroft heads to the door. His umbrella claps the cement smartly, counter-melody to his steps, and he uses the handle to knock.

Rat-a-tat Tat.

Mycroft barely stops himself from humming. Soon, very very soon, he'll be with Sherlock.

...

Mycroft is not ready for the surge of Alpha-instinct that swamps him when the door opens.

He knew.

Intellectually, he knew.

Knew how Omega heat drove Alphas mindless, caused riots and rapes.

He knew the man Sherlock had chosen to trust before his brother arrived was, unexplainably, Alpha.

Mycroft had blithely imagined it would be like the rest of the time; his inner Alpha sniffing around the baseboards of the empty room in his mind Mycroft locks him in.

Mycroft was wrong.

When the Holmes Estate door cracked open, Mycroft's Alpha went _mad_.

Mycroft is caught with his guard down, suddenly frantic, trying to prevent a disaster.

 _Omega! My omega!_ Mycroft's Alpha rose bristling, sniffing the air.

Then...

 _ALPHA._

 _Enemy._

 _Take him down._

Mycroft's inner-Alpha crashed right through the wall holding him in an explosion of splinters. It lashed it's tail and growled. Bloodlust. Rage.

 _ALPHA. ALPHA. Wrong. No. Bite. ALPHA. Nooo. Omega. **Mine**. _

_Fight-fight-fight-fight-fight-fight-fight-_

Frothing at the muzzle, Mycroft's Alpha had momentarily wrenched control from his unprepared intellect.

Mycroft maintains just enough conscious restraint to force himself to stillness. Locks his eyes on the bare feet in front of him, not daring more direct eye-contact. Mycroft is standing too straight, he knows it; every single muscle in his body is tensed, obviously posturing. _Primitive_. Disgusting, he is not an animal, goddammit!

Mycroft can't help it though. It is taking more strength than he thinks he has not to hurl himself at the other man.

 _Alpha. Fight._ _ **My Omega.** __Alpha_ _._ _Take him down. Fight-fight-fight-_

Mycroft knows he waits too long, motionless on the doorstep; knows it with some analytical part of his psyche that is not influenced by the Alpha's rage.

 _Fight-fight-fight-fight-_

And yet, it is _torture_ to control the outraged Beast. Mycroft squashes the instincts, forces them down. Fights an inner-battle that he mostly manages to keep from showing on his face. He hopes.

Mycroft is getting angry. This is ridiculous. The bestial urges will not control him.

The Alpha's anger is full of slobber and sharp teeth. Mycroft's anger is a cold slithery thing, that wraps itself around it's prey and gradually tightens the noose. Annoyance is a good thing. It gives him leverage over the raging mound of unrefined instinct that is his Alpha.

Finally, finally, _too late_ , Mycroft gains enough control to speak.

"Detective." He grates.

He forces a grimace intended to be smile, finally stamping his inner Alpha down enough to be able to draw a full breath.

Mycroft is sweating. He hates sweating.

Cautiously, feeling his Alpha shudder ominously, Mycroft raises his eyes.

"Mycroft." Lestrade answers warily.

He knows. Damn.

Oh, the detective knows. His eyes pierce right through Mycroft's sham at civility. His posture remains carefully neutral, his voice vibrant yet non-threatening. Strong, unintimidated; somehow gentle and trustable too.

Now that the red haze is settling, Mycroft can see the deliberate aura of leashed power Lestrade cultivates. Years of succesfully coaxing frightened victims to tell their story. Too long hours at work. A failed marriage. Effortless domination, when he needs it. Strength. The thrill of the chase. Cowing lesser Alphas into admitting whatever secret the investigation needs.

Alpha.

Very, very powerful Alpha. With such good control of his instincts that he has managed not to respond to Mycroft's slip. Most Alphas would have been snarling in his face right now. Probably a few Betas with an attitude too. Not Gregory Lestrade though.

It is rare that Mycroft faces an equal. Or what _might be_ an equal. Which is probably why, combined with the omega scent, his Alpha has nearly provoked a scene.

Omega.

Sherlock.

Oh god, Sherlock.

...

Mycroft swallows, tries to work moisture back into his dry, dry mouth.

Lestrade watches him, standing tall in the door. He is taller than Mycroft. It is annoying.

Just when Mycroft is about to make a snide remark, or maybe apologize, the detective seems to decide he is in-control enough and opens the door wide.

Protecting Sherlock. Making sure Mycroft is not overwhelmed before letting him in.

Mycroft can't help an admiring nod, yanking the chain tighter around his Alpha.

It responds restlessly; tugging, more intrigued than angry now.

 _ALPHA. Strong._

 _Enemy?_

 _Fight?_

Mycroft ignores the Beast's hesitation.

Sherlock waits.

...

Lestrade stays in the doorway, blue eyes seeing too much. He forces Mycroft to pass much too close to his warm body on the way in.

Mycroft smells him as he does, gun-metal and coffee.

His Alpha whines, turning in a tight circle. Mycroft ignores the clenching in his stomach.

"Where's Sherlock?" He asks instead.

His voice is better, smoother. Almost himself. The pheromones are stronger inside the house.

Omega.

Heat.

Mycroft's prick feels heavy; he is aware of his balls, swinging sticky with every step.

Gregory closes the door. He is still calm, artificially collected as he heads to the kitchen.

"Still knocked out. He should be up soon."

Mycroft follows Lestrade into Mummy's kitchen. The detective's body is lean and muscular, under the jeans and checkered shirt. He was not working then; Sherlock surprised him on a day off.

Lestrade's hand rubs the back of his neck. Probably, he can feel Mycroft staring at it. The Alpha howls, forlorn and wild, and it is disconcerting. Mycroft wishes it would shut up.

"Do you want a drink?" It is strange, _ironic_ , that Lestrade is playing host in Mycroft's own family house. Yet he was there first, and he looks very at ease in the sunny kitchen. Domestic.

Does Mycroft want a drink?

God yes. His father always has fine scotch. There is sure to be a few bottles of the Chardonnay his mother favors too.

The Alpha lunges inside him, half-heartedly, at the sight of Lestrade turning around and looming too close. Again.

Mycroft sighs, regret on his thin features.

He is perilously close to losing it. He shouldn't allow himself a real drink.

Sherlock.

Lestrade.

Sentiment, a murky greenish pool. Lust, an endless acid sky.

Alcool will blur the edges a bit.

Mycroft sits on a too-tall stool at the counter.

"Tea please." He says, almost keeping the bitterness from his voice.

Lestrade smiles warmly. Proud.

He knows. The detective _knows_ the struggle.

He is pleased Mycroft resisted. He busies himself fixing a cuppa. The water is already hot, a half-drunk floral porcelain cup on the counter Mycroft notices only now. Unforgivable. Mycroft is not a fucking teenager; he should be able to _think_ , even with his hormones raging.

The silence is filled with Lestrade's approval.

Mycroft's Alpha basks in it, panting with great breaths that make it's rib-cage move.

...

Mycroft takes a sip.

Strong, too much sugar. It soothes him anyway. Lestrade's hand did not shake as he handed it to him.

Strong.

"Why..." Mycrofts starts, then has to stop.

He does not know how to finish the sentence tactfully. He should have thought it through before he started.

Stupid.

Mycroft can't think, his mouth clogged with Omega, Heat, and Alpha, Alpha. He's half-hard now, in his mother's kitchen at two in the afternoon, waiting for Sherlock to regain consciousness. Sherlock, who is _dripping leaking writhing_ with his first heat, waiting to be fucked. No, don't think of that. Bad enough that he can smell him. If he allows the visual to fill his mind, Mycroft will lose it. He takes an unsteady gulp of too-sweet tea, wishing his hands didn't tremble.

Mycroft's dick kicks, in his pants. His Alpha is back to pacing, all it's hair on end. _Ready_. God.

Mycroft presses his wide lips tightly together.

Lestrade, surprisingly, comes to his rescue. He fills the silence with words.

"He showed up on my doorstep at home yesterday, you know. I'd given him a few cold cases, a month ago. When he said he was clean."

He pauses, and his eyes flick over Mycroft. Evaluating. Intelligent. The cop is peaking true.

"That was your doing, was it?" Gregory asks.

Mycroft nods, refusing to share more.

"Good." Lestrade's voice is warm and his approval is doing funny things to Mycroft's Alpha again. There is too much understanding in them, weariness from long years on the Force. But it's not that. It's more.

He looks at Mycroft, and there is gentleness. Not pity, but something comforting, welcoming of Mycroft's repressed emotions. Mycroft is the Iceman. He has no friends, no lovers. No-one looks at him like that... No-one notices him. No-one, except Lestrade is doing it now, when Mycroft is so so close to drowning. The undiluted _compassion,_ it chokes Mycroft; his throat knots with unexpected tears.

 _He knows_. Greg knows how hard it is to watch someone you love destroy himself. He is listening, ready to take on part of the burden if Mycroft wants it.

Mycroft licks his lips, cursing his eyes for swimming with treacherous unshed moisture. God, he wants to spill the angst out. Lay his broken heart in Lestrade's hands, let him support the too-big pain for just a few minutes.

He won't. Mycroft wavers. He barely knows Lestrade.

He won't.

He won't.

Lestrade just waits, patient, and it makes the urge even worse.

No-one listens to the good boy, the strong brother who controls himself, who studies and fulfills expectations. No-one thinks he needs it. Mycroft's world has always spun around turbulent Sherlock.

He sniffs hard, looking down at the counter because he can't stand Lestrade's gaze. _Intense_. Mycroft feels exposed. The words are on his lips. He swallows them down.

He won't.

 _Weak_.

Sherlock does not need weak. Sherlock needs strong, Alpha.

The moment stretches, unbearable. Then Lestrade decides to continue, sparing Mycroft to scrape his raw emotions together. _God he is a mess today._

"Sherlock solved them all of course. I've had him on a crime scene or two since." Greg laughs, toying with his cup.

"Well." He amends. "Sherlock showed up at a few scenes. He's quite good."

Lestrade stares into space. A smile still tugs at his lips.

Both men sip their tea.

...

Mycroft is calmer. Sunlight shines in a wide rectangle across the tiles of the floor. Lestrade gathers himself, finishes musingly "I might consider having Sherlock help me on a semi-regular basis. A consultant of sorts."

Blue eyes suddenly lock with Mycroft's and time freezes again.

"Heck of an attitude though. I always thought he was Alpha." Greg admits. "Until he barged into my place, more than halfway into heat, yesterday. His first heat. Christ. Do I even want to know how he got my address?"

Mycroft shrugs. Answers the tediously obvious question first.

"He's Sherlock." He says.

And the detective nods as if that statement actually makes sense.

"What I want to know." Mycroft adds. "Is why? Why you? Why show up at an Alpha's door, asking him to take him to another Alpha? It doesn't make _sense_!"

Inconceivable. It amounts to the ultimate tease. Lestrade should not be so calm. He shouldn't even have called Mycroft, or opened the door for him. His Alpha must be _screaming_ for him to keep Sherlock all to himself.

Sherlock, in heat.

"What did you do to him?" Mycroft asks, and his voice is harsh again.

Lestrade does not seem bothered by the implications. He shouldn't be so calm. It's not fair.

"I listened to what he wanted. What he needed. He slept a bit, I fed him breakfast. Then I phoned you, and I took him here."

Mycroft's dark eyebrows rise incredulously. Lestrade's eyes sparkle.

He admits. "I tranquilized him... With my service injector. Didn't want to risk full heat in a car. Now I'm gonna have to find a way to explain that one to my superiors!"

 _Greg spent three hours, locked in a closed vehicule with Sherlock in heat._

Bathing in his scent. Hearing his breaths. Mycroft is pretty sure that even medicated, an omega this much in heat would have made little noises. His brother is too far along not to.

Mycroft imagines Sherlock's long lashes, fanned on his sharp cheeks while his head rolls obscenely with the bumps in the road. Drugged. Those plump lips, artificially slack. Helpless. Was he strapped in almost upright? Or curled up in the back? _Ready_. Hips shifting, maybe humping the car-seat a bit; instinctive search for friction, for relief. Relief Sherlock will not find until he is stuffed with an Alpha's cock.

Christ. Mycroft is fully hard, and it aches. He adjusts himself efficiently, hidden under the counter. His hand wants to linger, to stroke and press and soothe. Mycroft doesn't allow it to.

 _Torture_.

Mycroft picks up his luke-warm tea and takes a swallow. Bitter dregs and too much suger. He grimaces.

He does not know how Lestrade managed to stand it.

Lestrade, who is too calm.

Unbidden, Mycroft takes a deep deep inhale, scenting the other Alpha. Lestrade allows it. He leans closer obligingly, elbows on the counter-top. His eyes don't sparkle anymore. They are dark, dark, dark.

After-shave, pleasant if fake.

Musk, darker than Sherlock's.

 _Alpha_. Like an aged wine, oak and tannins coating the back of his tongue. Mycroft closes his eyes, greedily drags air through his open mouth.

 _Alpha_. Arousal. Like a shot of port in a bitter black chocolate cup. Intriguing. Not as decadently pleasant as Omega, but not repulsive either.

 _Alpha_. An acquired taste, perhaps.

Mycroft leans even closer to Lestrade. He is aware the other man is scenting him back, air whuffing over Mycroft's cheek in a ticklish draft. There is a hint of sound from Lestrade, not quite a groan but some primal throaty sound that rumbles under the Alpha's exhales.

It is making Mycroft dizzy. It has been years since he indulged in such animal pleasures as scenting. And Mycroft's Alpha is not going beserk around the other Alpha. It is attentive. Fascinated.

The inner-Alpha wants more. It wants to nuzzle Lestrade's neck, wants scent him without his clothes. Wants to taste him.

 _Alpha._

 _Strong._

 _Aroused._

 _Ally?_

Mycroft sits back suddenly. He needs space before he does something stupid, like kiss another Alpha while his brother is in heat upstairs.

Lestrade looks shaken. He runs a hand through short salt-and-pepper hair. It is not as steady as it was earlier. There is a large bulge at the front of his blue jeans. Mycroft thinks it's been there all this time, but he didn't allow himself to look earlier.

Three hours in a car with Sherlock in heat.

God.

Mycroft reaches long fingers, unthinking; he just wants to touch the wiry fore-arm. Lestrade jerks back. His eyes flash.

"Don't." he commands, and there is gravel in his voice.

Mycroft sees then. He knows, suddenly, how strained Lestrade's control is, despite appearances. Of course it is! He is only human. _Alpha_.

Three hours, in a car with Sherlock in heat. For nothing.

Dear Lord. What a mess.

Mcroft offers to replace the godamn service injector. It's the least he can do. Being a minor governement official, Mycroft will ensure the detective suffers no consequences for what was actually a brilliant choice, even if it is illegal.

Time floats a bit, an awkward shyness between the two men that wasn't there earlier. Mycroft's Alpha is fucking preening, slithering through his mind with an annoying pleased flurry of movement designed to seduce Lestrade. What the heck?

Mycroft can't fucking think, what with Sherlock and heat pheromones and now same-gender attraction. He's never been homosexual.

Most people assign him the _asexual_ label. Mycroft doesn't correct them. He _wishes_ he were asexual; life would be so much less complicated without the lustful pulsions.

Asexual. Mycroft isn't asexual. He is simply meticulous about refusing to act on the urges. And now it seems that Mycroft might be at least bi-sexual too.

Lestrade clears his throat a few times. He refuses to meet Mycroft's eyes.

Suddenly, the power balance has flipped.

After too long of fidgeting and avoidance, Mycroft steels himself.

"We should probably adress _this_..." He does not know how to call the _pull_ between them, unnatural for two Alphas, so he flaps his hand around. Lestrade nods tightly.

"Before Sherlock..." Mycroft adds, softly.

Sherlock. In heat.

"Yes." Greg nods. He squares his shoulders. Mycroft suddenly regrets pushing for resolution. Of course, Lestrade is not a coward. He has trained extensively in how to react in high-pressure situations.

"Are you gay?" Lestrade asks gruffly. Words straight to the point, his blue eyes are pinning Mycroft mercilessly.

Mycroft holds the gaze with a coolness he does not feel.

"No." He answers honestly. The pull is still there, stronger now that they are locked in eye-contact. Mycroft's Alpha is keening inaudibly.

"I've never... Before..." Mycroft is horribly incapable of forming complete sentences today.

Mycroft draws a shuddery breath. Lestrade is tense, jaw clenched. Mycroft still wants to kiss him.

"What is your Alpha's reaction to all this?" Mycroft asks quietly.

He breathes through his mouth, subtly getting more of Lestrade's addictive scent. He wonders what Greg would do if he tried to touch him again. He really wants to. _Really really_ wants to. Not sexually, not really. Mycroft opens and closes his fist, fingers loose on the counter; he tries to dispel the need without actually reaching for the other Alpha. His whole arm is fucking tingling.

Lestrade's eyes narrow, then shut decisively. When they open again, they are almost black, the pupils dilated obscenely.

In sync with his Beast.

The tingles are spreading, running rapid-fire everywhere just under Mycroft's skin.

God.

He can feel the power of Lestrade's Alpha. It does not frighten him. Nor does it create the urge to fight this time.

Lestrade has been very, _impossibly_ , good at taking care of Sherlock.

Mycroft's Alpha recognizes this and now everything is _changed_ and confusing.

"Yours?" Lestrade rumbles, voice too deep.

Mycroft can't let his Alpha take control.

He can't.

He won't. He doesn't dare.

It's only fair he try.

His Alpha is being perfectly behaved, sensing the unique opportunity. It waits.

Lestrade waits too.

Mycroft wants.

He can't.

He won't. Mycroft's head hurts from the tension.

He hesitates. It is like being on the edge of a cliff. Mycroft tries to convince himself to make that leap.

Lestrade's Alpha regards him calmly with it's too-dark eyes. Centuries of instinct carefully leashed in the kitchen. Greg is taking quite a risk; it is extremely dangerous to merge at the moment because there is an omega in heat so close by. Mycroft envies Lestrade's healthy relationship with his Alpha. He must truly trust his Beast.

Mycroft does not trust his Alpha. He has spent his entire life suppressing it.

Lestrade waits.

Mycroft is sweating again. He hates sweating.

Mycroft does not trust himself.

He crumbles, hiding his face in his arm. The counter is smooth and cool against his heated forehead.

"I'm sorry." He mumbles, voice muffled by his elbow. "I can't."

 _I won't._

Greg and his Alpha make a sympathetic sound, like a grumble. Suddenly, there are strong fingers in Mycroft's hair. Stroking lightly, then with more confidence when he doesn't push them away. It feels good. Soothing.

The gentle caresses go on and Mycroft melts.

His spine is turning to water, his anxiety lulled away.

He floats.

Relaxed. _Better_. Safe.

The fingers stop.

Mycroft's head is too heavy to lift. He returns to himself slowly. Lestrade has moved around the counter.

Sometime.

Mycroft missed that happening.

Greg stands right behind Mycroft's bent over form on the high bench. Mycroft can feel the man's body heat, radiating so close. He is swimming in Greg's Alpha pheromones and he hadn't even noticed. Strange.

The detective leans closer. He speaks softly in Mycroft's ear.

"Do you know what my Alpha says?" It is a wonder he can form full sentences. Mycroft is incoherent, distracted by Lestrade's hand at his nape. Not doing anything. Just resting there, heavy and warm.

Mycroft sluggishly forces himself to pay attention to his own Alpha.

Mycroft realizes his Alpha is just as out of it as he is, splayed unashamedly on it's back with it's tongue drooping out one side of it's mouth.

Completely relaxed.

Shit!

Showing his soft furry belly.

Oh no.

 _Submitting_.

Mycroft jolts, panic jerking his self-awareness back.

No, no, no! He is Alpha, Greg is Alpha, he can't allow-

He makes a strangled sound, shoulders tensing in preparation to throw the other man off. His Alpha is up on all fours, looking around wildly for a danger it does not see.

Lestrade's hand clamps down on Mycroft's nape. Hard. _Strong_. Implacable.

Mycroft groans, from deep in his chest. He slumps again, eyes rolling upwards with how _good_ , how right it feels.

His Alpha drops immediately at the pressure, four legs giving out instantly. It grovels on the ground, quivering. Not fighting the domination at all. _Traitor_.

Mycroft's mouth opens to speak, even if he has no clue what he wants to say. Greg's hand squeezes again, pressing against the tight tendons tied to the base of his skull, and Mycroft's attempt at arguing dissolves into smoke. He groans again, _embarassing_ , and vaguely tries to gather the will to protest.

"Ssshhh." Lestrade's face is practically in Mycroft's shoulder as he soothes. His iron grip never fucking lets go.

"Don't fight it." Mycroft thinks Greg is kissing him lightly, along his ear, but he is shaking too hard with conflicting feelings to be sure.

"I've got you." And Mycroft's Alpha is whimpering, reveling in Greg's dominance. Happy, _begging_ , tail wagging and penis hard.

"Do you know what my Alpha says?" Lestrade sounds a bit annoyed that Mycroft is still trying to control himself. Failing miserably and nauseous with denial but he won't go down easy.

And okay, that was a lick, down the side of his jaw. Mycroft's head rolls, stretching to the other side. Elongating his neck. _Presenting_ , good grief.

Lestrade licks at Mycroft's collar-bone, little kitten swipes and wet sucks. For a brief instant, teeth press against his skin, hard and smooth.

No. NO. Mycroft invisibly struggles harder, flailing inside his head. It is useless. He can't pull away.

Mycroft is about to receive a bond-bite from an Alpha and his own Beast is _gagging_ for it.

Greg's lips move away. It costs him, Mycroft can feel him tremble; tremors travel from where his hand still holds Mycroft down. Greg ignores the body shudders, caused by the pure intensity of the moment. Mycroft is having them too, and his erection is sending little bursts of pleasure at the hint of friction.

"My Alpha says..." Greg's words are slurred. He swallows.

Agony.

"Pack." A rough whisper.

Light explodes behind Mycroft's closed eyelids. _Pack_.

Yes.

Mycroft's Alpha agrees, unequivocal and certain as only an animal can be.

As unlikely as it is, what with Sherlock in heat, _or maybe because of it,_ Mycroft's Alpha has recognized Lestrade's.

Pack.

Family.

Trustable.

All the fight goes out from Mycroft.

Pack.

 _Yes_.

He floats again, glorying in waves of peaceful acceptance, finally one with his inner-Alpha.

Lestrade makes happy sounds behind him, his hand finally releasing Mycroft's nape to stroke up and down his back.

Good..

 _Pack_.

Mycroft doesn't have to worry. His Alpha's got him.

Greg.

Mycroft's Alpha.

...

Mycroft blinks back to himself slowly, consciousness building in paper-thin layers until he feels strong enough to sit upright.

Lestrade kisses his hair once then pulls away.

Mycroft's face feels puffy, like he's over-slept or he's been crying. Maybe he has. The past half hour is all blurred together.

Greg.

Pack.

 _Right_.

Greg moves back around the counter. His Alpha is gone, held back inside again. Mycroft's Alpha can feel it and it makes it happy.

Greg's Alpha lives in a forest, full of moving shadows and little wild noises. Mycroft does not know how he can be sure of this, but he _is_. He suddenly feels guilty for the bland box he's been keeping his Beast in all these years. His inner-Alpha licks his hand decisively. It is not angry; it did not know either.

Mycroft adds a shining bowl of water and a heap of blankets to the enclosure in his mind. His Alpha's yellow eyes mock him. Mycroft tries better. Changes the walls out for a sunny field of waving grasses. He hesitates, then settles for a loose fence of silver wire. He mentally apologizes to his Beast. He can't let it roam free. He'll try. It will take time.

Mycroft vows to work on his relationship with his Alpha. It is happy. It barks at a funny-shaped cloud then lopes over to investigate the blankets.

Mycroft focuses on his physical surroundings again.

Greg is watching him with a little smile on his face. Mycroft swears he hears the distant happy howl of the other man's Alpha.

Now that they are back to being two regular guys, things are strange. Greg seems a bit shy, a bit sheepish, but his joy shines through from deep inside and makes everything all right. Mycrofts mouths a silent _"thank you."_

They hadn't planned the bonding; there will be consequences and long conversations to be had.

Later.

 _Pack_.

Lestrade maintained enough control not to actually bite, so in theory the bond can be undone. If they fight it, for months and months, maybe years, it will gradually fade. It will be unpleasant. For both of them. It is doable. Maybe.

Mycroft does not want to fight anymore. He is tired. They'll make this work. He is not very happy with the hierarchy that was established, but Mycroft's Alpha is adamnant that it's what he needs. Mycroft decides he won't challenge Greg for dominance.

It's impossible to go back, anyhow. It is harder even to regret the pack-bond when every fiber of both their beings is so satisfied at how right it is.

"Well."

Both Alphas jump and look to the kitchen door. Sherlock is leaning there. He is impeccably dressed, in a tight fitting grey shirt and black trousers.

"How interesting." Sherlock seems normal enough, voice aloof and chin high. Maybe there's been a mistake. Sherlock is supposed to be omega. Sherlock said he was in heat.

Mycroft gulps, feeling like a kid caught misbehaving.

"Are congratulations in order then, brother-dear?"

* * *

 _Cliffhanger, sorry not sorry. The story needed to breathe. We are getting closer to the porny goodness!_

 _Next up, we meet Sherlock!_

 _I appreciate feedback, especially since this is a new fandom for me!_

 _xxx_

 _FrenchCaresse_


	3. Living room conversations

_You guys are killing me, ya'll! It is so nerve-wracking to post in a new fandom and not get any feedback! Someone please put me out of my misery! Pretty pretty please!_

 _Posted a third chapter in a week because I have given up, these characters are pushy._

 _There is some deep stuff to get through before the sex. So warning for **intense angst.** Upset Sherlock finally being honest, overwhelmed Mycroft, Greg is the best; a little **mention of drug use.** I don't want to tag this properly not to give too much away._

 _Be ready, this chapter is an emotional free-fall._

* * *

Sherlock's words ring harsh and mocking in the quiet kitchen.

His brother's words are cutting, agressive like always. Always pushing, forever _challenging_.

This is not how today was supposed to go. Mycroft is taken aback by the depth of his deception.

Today, things between them were supposed to be _right_. Sherlock was supposed to finally let Mycroft be close to him. He'd recognized his need for Mycroft, so Mycroft stupidly imagined Sherlock was going to let him protect and help him. Mycroft had hoped he could at last be the big brother he's longed to be during all those years of misunderstanding.

But Sherlock is not friendly and grateful.

He mocks Mycroft again, for displaying _sentiment_ ; probing triumphantly at any weakness he detects.

Sherlock is being... Sherlock.

It _hurts_.

Mycroft can't speak. Too much has happened today, Mycroft is stripped bare, worn down by emotions and the bonding. He can't fend off his brother's sarcasm. The best he can do is keep his face blank, stoically silent.

Lestrade bristles for him; Mycroft feels it through their connection before the man speaks.

 _Pack_.

His Alpha has his back.

"Sherlock." Greg's voice cracks sharply, more than a hint of Alpha-Command running through it. It makes Mycroft's insides tense, as if his very nerves are wired to his Alpha's wishes.

 _"_ **Behave** _." Alpha-Voice._

Mycroft swallows. He is happy to be sitting. He has never been affected by an Alpha's command before. _He has never had an Alpha before._ Even though the disapproval was not directed at him, Mycroft's inner-Alpha is flat on it's belly, ears laid back and eyes round marbles.

Mycroft lifts his head to smirk at his brother, deciding to examine his ambiguous feelings towards Alpha-command later. He is reasonaby certain Lestrade won't use the privilege too often.

...

Crap.

Sherlock is half-crumbled against the door-frame, head hanging with his dark curls in his eyes. All the false bravado from earlier is stripped away. Sherlock looks so so vulnerable suddenly, breathing in rough sobs.

Omega.

In heat.

Greg looks mortified.

"Sorry." He breathes. "I'm sorry Sherlock, I shouldn't have done that."

Sherlock's fingers on the ancient wooden door-frame are white with strain. Spider-legs, clutching desperately; the only thing keeping Sherlock up-right.

Greg is blushing, it makes Mycroft want to lick his face. Remorse is pouring off of him and the officer frets. "Will it make it better... or worse... if I touch you, Sherlock? I really want to hold you now."

Sherlock licks his lips, shakes his head.

"Sit? Please?" His voice is only a thread but it spurs Mycroft into action. He rises and leads his brother to the living room.

Sherlock moves clumsily, and when he stumbles in the corridor Mycroft finds himself closer to him.

Too close.

Ready.

The scent of _Omega, Heat_ , smacks him in the testes but Mycroft grunts and otherwise ignores the sudden revival of his dick.

He pushes Sherlock down onto the sofa. The taller man goes unresisting; he leans foreward with his fore-arms braced on his knees, graceful hands hanging loose between them. Mycroft wants to sit beside him, but he worries he won't be able to stop himself from touching Sherlock. He settles for pacing tightly.

Minutes pass.

Greg is still in the kitchen, obviously giving Sherlock some time to recover from Alpha-Voice.

There is tension in the air, so thick Mycroft can almost see it shimmering off the tasteful wallpaper.

The time-out works.

The shivers gradually stop and Sherlock's eyes are focusing on Mycroft. Too sharp again. Mycroft is boiling in his suit. He removes the jacket with a few efficient tugs, folding it over and setting it on the back of Mummy's armchair. He still looks put together in his shirt and vest, maroon tie a tad loosened. He rolls his sleeves, three crisp turns; Sherlock is fucking devouring the sight of his brother undressing.

Greg comes in, and Mycroft is glad. _His Alpha_. Greg gives him a smile and hands a tall glass of cold water to Sherlock like a peace offering.

Sherlock smiles too, enigmatic, _such_ _luscious lips just made for kissing,_ and whispers " _thanks_."

Sherlock drinks. His adam's apple moves. Mycroft imagines that long throat, taking in an Alpha cock.

He turns swiftly, puts a couch between him and the omega in heat. Mycroft walks in tight loops, trying to work off the nervous energy. _Mount, Fuck, Take._ He locks his hands together at the small of his back. He left his umbrella in the foyer.

Greg seems to be back in control. Mycroft can barely feel his pack leader's Alpha, even if he concentrates on the bond.

They are all on edge, hormones running rampant and with a fresh pack-bond further muddling things.

Greg apologizes again, swearing he won't abuse Alpha-command. He explains that with a fresh bond he hadn't been able to think before defending his mate when Sherlock hurt him. Mycroft winces, turns to stare out the window. He never acknowledges that his brother's words touch him. He is the Ice-man.

He can feel Sherlock watching him; evaluating, quickfire new connections sparking. Mycroft does not know if that is a good thing.

Finally, Sherlock shrugs; Mycroft can hear his shirt rustling against the couch. He assures Greg not to worry. Sherlock doesn't sound angry at Greg's slip, even if it was obviously horrible to be forced to heel like a pup. Apparently, transparency has worked well for Greg's relationship with Sherlock. Huh.

"How are you, Sherlock?" Greg's voice is still cautious, subdued. He steps into the room. Mycroft turns around quietly.

"All right, I guess." Sherlock shrugs again, staring into his empty glass. He sets it down on the floor by the couch.

"Uncomfortable." Sherlock continues. "It is manageable."

He frowns.

"For now." He adds.

Mycroft hears the slight waver in his voice, the doubt at the admission. Sherlocks _hates_ not being in control. His body is staging the ultimate betrayal. Of course Sherlock is anxious.

Mycroft is still tongue-tied.

Greg sits on the coffe-table in front of Sherlock, his posture carefully non- threatening.

Mycroft knows this is his "I'm a good cop, talk to me" personna.

Sherlock sees it too, Mycroft can tell by the twitch of his nose.

It works anyway.

Sherlock unwinds a bit, some of the brittleness in his body slipping away.

Mycroft remembers that floating feeling he experienced when he submitted and let Lestrade guide him. His inner-Alpha is proud of itself.

Good.

 _Pack_.

Mycroft trusts Gregory. He hopes Sherlock can trust him too.

"Did you already know you were Omega?" Greg asks. A direct question, no useless coddling.

Sherlocks eyes flicker around the room, hesitating.

His phermones are deepening, just from being in the same room as two Alphas. Mycroft can smell the change. _Heat_. Progress. Surely Sherlock must feel it.

His brother sighs, and when he speaks Mycroft knows he will answer truthfully.

"Yes." Sherlock says. He is panting a bit.

Greg does not seem surprised. He nods.

"How long?"

"Since I've known?" Sherlock barks a laugh that feels like a paper-cut. Tiny but smarting like heck, a bead of blood hinting at soft mushy flesh beneath.

"Years." Sherlock speaks too fast, like he does when he's deducing. "I think even in childhood, I knew. It's why Mycroft attracts me so much, maybe. At adolescence I deleted the urges, barricaded that wing in my mind-palace. I tried. "

Sherlocks cheeks are pink. "I tried. I tried so hard. I tried to convince myself I wanted to mount, to chase. I almost believed it."

His eyes, grey and troubled, settle on Mycroft standing near the wall. "I liked pushing you well enough, _brother_."

Mycroft doesn't answer. He tries to keep his face blank at the confirmation of what he already knew. Sherlock truly _was_ seducing him on purpose.

Sherlock fidgets. He never fidgets, usually. There is sweat at his hairline.

Sherlock finishes quietly, _defeated,_ adressing Mycroft rather than Greg. _"_ But I knew that if I ever _did_ catch you, it would be the other way around in the end. I couldn't win. Even if you had broken, I still couldn't win. I wanted you to fuck me. Like a pathetic Omega whore. "

Greg is sweating too. Mycroft can see the little curls at his nape darken.

Sherlock is still agitated. "You wouldn't let me have my way, Mycroft, and that was _infuriating_. Anger was good. It made me feel strong. Angressivity is an Alpha trait. It kept me going for a few years."

Sherlocks fingers flick open three buttons on his shirt in rapid succession. Mycroft does not think he realizes he has done this. A triangle of ivory skin is bared, tempting the Alphas. Sherlock's gaze is still turned inward, frowning at his troubled years.

"My body wouldn't change. Not how it should. It was _wrong_. Every morning, I hoped to feel that knot at my cock. Maybe the hormone levels were finally high enough."

Sherlock won't look at them now. His eyes dart around the living room, looking for escape before concentrating furiously on an empty spot on the wall. _Prey_. Omega.

"My knot never developed. It was never there. _Wrong_. Every day during puberty started off with deception. I never got used to it. I always expected..."

Sherlock holds his head in his hands, fingers tugging too hard at the silky locks. He does not seem to notice.

"Stupid." He spits. Mycroft doesn't know what to say.

Sherlock continues. " _Wrong wrong wrong._ I got taller, but I never got muscular. My pilosity never increased; stupid soft pale skin. I wanted to scratch it off. After a few years, the idiotic hope dwindled then disappeared. My body was broken. It was wrong, everything was _wrong_. I hated it; hated myself but there was no way to make it right!"

Sherlock's confession is clawing Mycroft to pieces. He is thankful for Greg's steadying presence. He does not think he could have faced this alone.

Sherlock grunts a bit, _pained_. His hand presses to his belly and he curls over a bit.

"Cramp." He answers the twin worried Alpha expressions watching him.

He shakes it off, anxious now to finish his story before his transport takes over.

"I thought drugs could help. And they did, at first." Sherlocks face closes. He knows how sensitive the subject is for Mycroft.

His eyes are soft, apologetic. "I lost control then."

Mycroft blinks. The room is blurry. He blinks again. His eyes burn. The tears won't go away this time. Mycroft has to press his thumbs into his eyeballs, hard, and hope no more tears rise. His self-control is precarious.

He looks up to see Sherlock crying softly, face hidden in his long thin fingers. Greg looks torn. He wants to touch the vulnerable omega; instinctively wants to hug him, but he doesn't want to spike the heat again.

Mycroft moves to sit on the couch by Sherlock. He doesn't touch him either. He can respect him that much. Mycroft wants to take his brother in his arms; he really really wants to. _Temptation._ Always _._ Greg's strong hand grips Mycroft's, squeezes tight tight tight. It helps. A bit.

"Oh, Sherlock." Mycroft doesn't even recognize his own voice. He is dizzy with the pheromones, this close to Sherlock.

"Can I hold you?" Mycroft asks. His own Alpha instincts are furious at him for letting an omega in heat cry.

Sherlock shakes his head furiously. He sniffs and wipes his cheeks.

"Sorry." He says under his breath.

His legs press together and then spread, his hand digging into the meat of his thigh; Mycroft can see the outline of a small hard Omega dick, unattended in his brother's trousers. _Unacceptable_. _Lick, suck, mount._ Mycroft's Alpha thinks.

"Sorry, sorry, sorry, sorry." Sherlock is repeating endlessly.

"Sorry, sorry, sorry. Stupid. Stupid. Stupid. Stuuuu-piiid." A hysterical sing-song that scares Mycroft. He's never seen Sherlock lose it. Not mentally disconnect like this anyway, even when he was buzzed out of his mind on illegal substances.

It's Greg who breaks him out of it, who places a warm hand on Sherlock's jittery knee.

Sherlock's breath catches and he sits straighter.

He nods. The flush on his cheeks spreads down his neck in blotches that disappear into his collar, Mycroft notices.

"Well." Sherlock's voice rings with false cheer.

"I'm off drugs now!" He says brightly.

"No ignoring facts anymore, right! My body is settling into it's natural state. I'm Omega!"

He means to fake light-heartedness, Mycroft thinks, but there is a faint wobble in his voice that gives away his discomfort.

The comment falls flat, lands with a thud in the tense room and Sherlock's face locks down. _Masks_.

Greg's thumb strokes Sherlock's bony knee-cap silently.

He is thinking. Mycroft can see the intelligence.

Mycroft can't think at all. He will need time to digest all that.

"I." Greg stops, frowns.

Decides he's right and says decisively. "I think you might be trans."

...

Sherlock is a pale statue with huge eyes, drinking in Greg's words.

"I'm not an expert; there are specialized therapists you'll have to consult, tests that will have to be done."

Mycroft is frozen. But he knows the truth of the statement the moment the detective says it. Trans-sexual. An Alpha in an Omega body.

Sherlock. Why did Mycroft never see it?

Greg is still speaking.

"It's just... that level of dysmorphia... You nearly killed yourself to escape it, Sherlock. If you ARE trans, there are hormone treatments, surgical options, support groups..." He trails off.

It's true. Trans people are a minority, but they exist. They have become more pro-active in recent years. Mycroft's vision of the political landscape shifts. If he tweaks legislature and pressures a few high-ranking officials, there are changes that can be made. Equality, more rights. Mycroft sees the way to that goal like a roadmap spread out. Connections, big and small spreading in a brilliant grid. All Mycroft need to do is a snip here, a push there...

Sherlock looks shocked. His processor has shut down. He chews on his lower lip, an uncharacteristic nervous tic.

"It's... Possible." He analyzes slowly. "I need more data; I'll have to reclassify years of evidence."

Another cramp seizes him, stronger than before because his hand instinctively reaches out, grips Mycroft's leg beside him in a bruising clench. Sherlock's breathing is labored. The omega hand on Mycroft is igniting a raging burn in his groin. Mycroft's hips roll once before he can still them. His hard-on twitches, again, and again, and again because Sherlock is touching him and _Sherlock is in heat._

The spasm is finally over, and Sherlock lets go, flexes his fingers; Mycroft swallows a moan. He supposes it's a good thing the contact is broken. He was half-way to knotting, untouched and in his pants.

"I can't deduce... Not today." Sherlock's voice is strained. His bum keeps clenching and releasing. Mycroft knows, he can see the fabric of his pants shifting.

"Of course not!" Greg reassures. "Just know that you're not alone. You're not a freak."

Sherlock shudders at that one and Mycroft remembers child voices taunting, mean and high-pitched.

"There's no rush to label yourself. Even if you _are_ trans, you've been passing as Alpha for years. You needn't change much; maybe a only a scent dampener to start, now that you've presented."

Sherlock looks thoughtful, then his face abruptly twists.

Sherlock gasps, "Oh God", folding over. His shirt stretches over his back, the fabric vaguely shimmery. Sherlock grips his ankles, face hidden over his knees.

His hips rock now, _needing_ , and Mycroft knows it humiliates his brother that he can't control his movements.

Sherlock is in heat and it _hurts_ him.

Greg waits, more patiently than Mycroft thinks he can, for the surge to pass.

"Getting stronger?" He asks as Sherlock slowly sits back up.

Sherlock nods. He looks haunted, scared. His jaw is clenched tight and his face is red.

"You need to decide who you want for your first time. Now."

Mycroft almost whimpers.

 _Traitor_.

Pack.

Alpha.

Mycroft almost whimpers because he knows if Sherlock picks Greg, he won't fight it.

It will kill him inside, but Mycroft can't, won't resist Sherlock's choice. Greg is a strong Alpha, with a gentle hand and an understanding heart. He is a good choice.

"Mycroft." Sherlock says.

His voice is firm. He sounds lucid enough.

Suddenly, he is kissing Mycroft and then it's all lips and growls and heat and ...

...

"Guess that's my time to leave!" Greg's dry chuckle covers a layer of rejection. Mycroft knows it and he jerks apart from his brother guiltily. Sherlock bolts right off the couch and out of the room, muttering for Greg to wait for something.

"I'm sorry." Mycroft says, and he means it. Greg deserves better than to be tossed out on his Alpha tail.

Greg smiles again. His face is shuttered, tightly in control.

"It's okay. I'll survive. Blue balls never killed anyone." Mycroft's Alpha is whining, whining, whining. It wants Greg satisfied.

"If there's anything I can do..." Mycroft blurts.

Greg stands. He towers over Mycroft.

"Are you offering to suck my dick?" The detective jokes.

"Yes." Mycroft answers thoughtfully. He wasn't of course. He hadn't thought of that. He's never...

"Yes." he says again. It's a genius solution actually.

"If it's what you want, _what you need,_ then yes, Greg, I want to suck your cock."

Mycroft is warming to the idea.

He sits straighter, eying the bulge that is right there in front of him. He takes a deep breath; tries to smell the musk, to detect the scent of pure undiluted Alpha. His Alpha.

"I can't promise I'll be very good, but I'll do my best." Mycroft admits. Greg is not responding, immobile in front of the couch.

"I might choke a bit." Mycroft warns. If the distorsion in his pants is any indication, Greg is HUNG.

"That... It's okay. Doesn't bother me much." Mycroft explains.

He reaches for Greg's belt, fingers grazing worn leather. The buckle makes a clinking sound when Mycroft tugs.

Greg backs away suddenly, wacks his knee against the coffee table and does a strange hobbling dance sideways.

"What?" Sherlock has walked in and he looks confused.

"Your brother is offering to suck my dick." Gregs tattles, voice rough.

"Oh." Sherlock says.

Then he stares into space, eyes glazing over. He looks between the two Alphas, and his face is eager, hungry.

"Oh." Sherlock says again. "I want to see that." He groans and his fingers press to his chest.

Greg backs away, circles the arm-chair, breathing hard.

"Okay." The Alpha promises, flustered and blushing again. "Okay. Another time. There... There'll be plenty of other times."

Greg is no longer composed. He is losing it, scurrying away in a panic.

Mycroft remains sitting, a picture of politeness in his goddamn impeccable shirt and vest. His smile is almost fake, oily and unappealing. Greg knows how undone Mycroft is though, can feel it through the bond and his Alpha. Mycroft licks his lip, staring intently at the detective. He really _was_ going to blow the other Alpha. The man is an enigma.

"I'm going now." Greg reaffirms. His palm cups his cock for a second, over his jeans. He must be aching fiercely.

Hours, in a car with Sherlock in heat.

Mycroft really really wants to suck him, now that the idea has been planted. The way Sherlock is looking at Greg is similar; pure decadence offered.

"Jesus." Greg swears. "I really really need to leave."

He sounds like he's trying to convince himself, to psyche himself up to actually act.

"Gotta go." He repeats.

"Before I can't." He mumbles softer.

Greg hurries to the door, rather desperately. His usual smooth gait is choppy; his mind is warring with his instincts and his body is stuck somewhere in between.

Omega. Heat. _Pack_.

Temptation.

Greg is wired tighter than he's ever been.

Sherlock throws a sealed evidence bag at him. Greg catches it without thinking, frowning at the unidentified contents.

"My underwear." Sherlock states helpfully. "For later."

Soaked through with omega slick, certainly.

God.

The brothers can see when Greg understands; a vein pulses on his forehead.

"Okay." he chokes. "Thanks. Bye."

The door slams hard with Greg's haste to retreat.

Mycroft is alone with Sherlock.

Sherlock.

Omega, at least physically.

Sherlock.

In heat.

Together.

* * *

 _The last chapter is pure kinky Heat sex._

 _It is also ridiculously long, so there might be a more normal delay before posting. It is fully written, but editing is proving to be a struggle. I keep getting overwhelmed and needing a break._

 _xxx_

 _FrenchCaresse_


	4. Living room conversations, without Greg

_Thank you, thank you, thank you to the amazing readers who commented or kudo'd. You are my inspiration and my motivation. And you saved my sanity._

 _The last chapter was extremely long, close to 15 000 words, but mostly it was soooo crazy intense. I couldn't even get through the whole of it and I wrote it! I have decided to split it into more manageable parts, that I am posting all at once. So feel free to devour them all like a mad-woman. Or take a break or two to, um, cool down._

 _Finally, this is where the tags come in. Twisted incestuous role-playing heat denial torture for your reading pleasure! Oh and some gratuitous asphyxiation, just because..._

* * *

...

After Gregory leaves, there is a strange unstable moment.

Anticipation.

Heat.

Together.

 _Finally_.

Remembering Greg's undignified exit, Mycroft feels a smile tugging his lips. Sherlock threw his fucking underwear at the detective!

A quick glance at his brother and suddenly the hilarity won't be contained. Mycroft laughs and laughs, joined by Sherlock. The whole situation is so unusual it is absurb and Mycroft's brain has given up, letting the tension ease through crazy cackles.

Sherlock flung his fucking underwear at Greg... for masturbatory purposes.

After Mycroft had offered to suck his cock.

The look on the poor detective's face!

The laughing fit keeps on for a while; Mycroft gasps and shakes, his belly hurting. He hasn't let go like that in years.

God it feels good!

Sherlock calms first, moving to perch stiffly on the sofa.

Mycroft joins him, muttering "Poor Greg." with a final humph.

Sherlock's lips twitch, but his face is strained, posture antalgic. _Cramp_. Again.

"Sorry." Mycroft says. He reaches a tentative arm around Sherlock's frail shoulders. Initially tensing furiously, Sherlock eventually relaxes. He slumps against Mycroft with a grateful moan.

Together.

Finally.

All is right.

"Tell me what you need." Mycroft whispers, hugging Sherlock closer. "Whatever it is... I won't hurt you, Sherly. I promise. I would never hurt you. You know that, right?" Mycroft's voice is gruff now. There are years of emotion behind the statement.

Sherlock simply nods, but his face is serious. He understands.

They sit for a bit, Mycroft reveling in the simple act of having his brother finally in his arms. There is much yet to be said, but for now this is enough. They are peaceful together. Mycroft's dick is still hard, but he hardly notices it. Minor inconvenience, easy enough to ignore.

Sherlock shivers a bit.

"I'm scared." He admits softly. Mycroft tightens his arms. Something slithers inside him, some dark interest.

Mycroft tamps it down.

"First heat..." Sherlock says. That _thing_ inside Mycroft rears it's head. He bites his lip not to make a sound.

The _thing_ inside wants to grow, take up all the space. It is not Alpha instinct or arousal, even if sends electric shocks right to his crotch; it is something deeper, scarier. Something rooted deep deep in his soul that is reacting to Sherlock's words. _Potential_.

Mycroft turns his attention inwards. He needs to understand what that thrill is to be able to disperse it.

Mycroft's hand rubs soothingly over Sherlock. His brother is still too thin, Mycroft can feel every vertebrae in his spine.

It reminds him of when Sherlock was younger, before it all went to hell. Tactile memory, rubbing his back just like when his little brother crept into Mycroft's bed at night, scared and shaking. Sherlock had never been like other children, afraid of monsters and nightmares. He had been frigtened of all the real possibilites; earthquakes and meteorites and armed robbery. Mycroft had held him, night after night, filled with fierce protectiveness. He had explained what adults believed Sherlock was too young to understand; taught Sherlock about statistics and probabilities in a low voice, until his baby brother's breathing deepened and he slept.

It's that same feeling that is filling Mycroft.

That strong head-rush of being responsible and invincible.

Somehow, that healthy emotion has blended with the years of repressed sexual longing.

Sherlock being vulnerable makes him seem younger. He is dependant on Mycroft.

 _First heat_.

It makes Mycroft's stomach tense with want; NOW his dick is hard to ignore.

Strong.

Alpha.

Sick. He shouldn't be reacting this way. Mycroft vows not to let his perversion affect his behavior with Sherlock.

His brother is watching him with his grey grey eyes, keen and piercing.

God. Mycroft attempts a weak smile.

Sherlock kisses him, and everything is buoyant and luminous for the next minutes. Like when they used to observe the pond in the summer sunlight. Fairy lights; blinking twinkles gilding the surface of the dark dark lake, unbothered by the murky depth of the waters.

Through the kisses, Sherlocks hand are busy. They tug at Mycroft's tie in hard yanks; he amuses himself by pulling his brother closer with red silk. Mycroft resists at first, just to feel the pressure where the fabric digs under his jaw.

Sherlock's eyes narrow, and with a deft flick of his wrist, he snaps the tie over his hand, _once_ , _twice_. NOW he has an unshakeable grip and a simple twist of his fist pulls the tie tight. Too tight.

Fuck.

Mycroft's breathing is very very close to being cut off and he is getting dizzy. Mycroft makes a choking noise against Sherlock's soft lips. His Alpha is panicking at the asphyxiation; _fight_ , it wants to get free NOW.

Mycroft doesn't move, remembers to keep his breathing as shallow as possible. His lungs are starting to burn. Sherlock wouldn't actually kill him, would he? His brother's face is cold, Mycroft can not read anything on it.

Adrenaline races uselessly through his veins. His hands grab instinctively, clutching Sherlock's fore-arms, but Mycroft doesn't do more than hold on. His face is ugly, tinting into dark red and his mouth gapes as he wheezes.

There is an odd peacefulness to Mycroft's surrender. His body jerks against Sherlock's through their last oxygen-deprived kiss.

Mycroft is losing his grip on consciousness. His vision blurs, the walls weirdly rounded like they are bending towards him. The pressure on his neck is vaguely reminescent of Lestrade's hold. Fuck. Lestrade.

Mycroft's eyelids flutter. Sherlock's knuckles are white from his unforgiving hold on the tie.

Greg will be so mad at Mycroft's lack of self-preservation. Probably the Queen too, but Mycroft finds he doesn't give a fuck about the Governement at the moment, even if it is his whole life. How interesting; petty human attractions, _pack_ , prove to be important after all when faced with his own demise.

Sherlock's face crumbles and he releases Mycroft.

Both brothers gasp for air, greedy greedy gulps. Mycroft coughs fitfully, returning consciousness and oxygen making his synapses snap alert. Everything is over-exposed now, after the dimness of strangulation. The texture of his clothing, the smell of Omega, the taste of blood in his mouth; _Mycroft hadn't even realized he'd bit his cheek._.. Mycroft rides the hormonal high, panting. His body shakes.

Sherlock's lips are moving all over his sweaty disgusting face, kissing Mycroft in silent apology. He tugs the tie up over Mycroft's head, catches his ears painfully, and throws it away. Mycroft is still recuperating while Sherlock removes his vest, leaving only his white shirt. Sherlock's fingers brush lightly over the zipper of Mycroft's pants.

Sherlock pulls away and arches an eyebrow. Mycroft is not hard anymore, his erection entirely gone.

"Didn't enjoy that?" Sherlock whispers.

Mycroft doesn't know how to answer. The primal rush of survival instinct was interesting, but it certainly wasn't a sexual thing for him.

"You owe me a tie." He rasps, fingering lightly at the tender skin of his throat. Fuck. That will bruise for sure.

Sherlock chuckles softly and kisses him some more. When he pulls away, their foreheads are almost touching and Mycroft has forgotten his turmoil.

Sherlock's cheeks are stained with two red splashes, and his eyes are too bright.

Sherlock.

In heat.

Mycroft smiles tremulously.

"You'll help me, right Mick?" Sherlock's thin fingers clutch at Mycroft's hand and he blinks slowly. His brother's eyes are wide, trusting. God, he looks so young.

That _thing_ inside Mycroft roars in his ears and he can't breathe for a minute.

Fuck.

Sherlock has pulled away, and his expression turns calculating, shrewd. He absently wipes the sweat from his forehead.

"Mycroft?" He inquires, and he is back to the cold adult Sherlock of the recent years.

Of course, he's deduced his brother. His first theory was wrong but now...

He knows.

Mycroft sighs deeply, closing in on himself.

"I'm sorry." He says, voice still hoarse.

"I don't know what..." But he _does_ , he knows now.

"I'm sorry." He says again.

"I'll... I'll go, if you want. Greg can't be far."

...

Sherlock's face is inscrutable, intelligent, even if his hips won't stop rocking.

Then he grins and pokes Mycroft in the meat of his arm.

"Mycroft has a kiiiii-iiiink." He teases. Sherlock's eyes are bright with humor.

Mycroft doesn't answer. What can he say? It's true.

 _Masks. Gone._

Sherlock chuckles breathlessly. He doesn't look angry. Mycroft is mortified.

His brother sobers suddenly.

"Are you a pedophile?" He questions.

A... Mycroft is horrified.

"No. No." He assures.

"God no." He can see how it is a logical conclusion though. He does not want pre-pubescent bodies. What he wants is...

"It's the innocence, I think. You needing me, depending on me... I wanted, for so long... The ultimate power trip, I guess. Sorry, my ego is out of control." He blunders awkwardly.

Sherlock is analyzing, his eyes narrowed. A cramp hits him again and he gasps; Mycroft rubs circles on his back, feeling helpless. He doesn't dare move his fingers lower like his Alpha wants; doesn't to dip below the waistband of Sherlock's pants and bury his hand in the warm wetness surely there.

Sherlock takes a shaky breath when the contraction is over.

He nods and confirms, wiping at his wet eyes.

"Daddy-kink. I can work with that."

Mycroft splutters, scandalized.

"You don't have to. God Sherlock, that's... I'm sorry, no! I'll control it, you don't have to..."

Sherlock looks much too wise and knowing as he kisses Mycroft to shut him up. First heat. For Mycroft.

"It's okay, Mycroft. It's normal to have things that trigger you. Haven't you ever exploited it with your lovers?"

Mycroft reddens. Dear God, don't let Sherlock deduce that last bit, let Mycroft keep his dignity, don't let him-

Sherlock gasps again. "You've never..." And there is honest shock on his face.

Mycroft won't look at him.

"No." He whispers to the abstract swirls of colour on the couch.

He doesn't elaborate.

He doesn't have to.

Sherlock's hands are in his hair, stroking the side of his face until he looks up.

"Me neither." He assures. "Well, I've never been taken. I played at being Alpha so I've fucked others before..."

"I stopped, after a while."

Darkness passes over Sherlock's expression, there and gone.

"It never felt right."

Mycroft kisses him then, open-mouthed and wet; he can't help it. Time distorts again.

Vague humiliation still makes Mycroft uneasy. Daddy-kink, dear Lord. There have been too many insights into his own dysfunction today.

"I have a kink too." Sherlock mutters against his lips.

"I like to edge."

Mycroft doesn't understand, so Sherlock explains.

"Orgasm delay. Get right to the peak where you can't hold back, then _wait_. Again and again, until my transport is unbearable."

Sherlock pants, and his hand moves to grip his dick.

Control. It makes sense, especially in the light of recent revelations. It's so... Sherlock.

"Usually alone." Sherlock continues, unaware of Mycroft analyzing him.

"With you..." He shudders. "Oh, the potential..."

Sherlock goes still, gathering himself.

Then there is a change in him, some minute shift in his posture or attitude. He is young and vulnerable again.

"You'll help me wait, right?" Sherlock pleads, and there it is. Mycroft reacts with his gut, deep deep thrill again.

He nods stupidly.

"First heats are long, huh?" Sherlock says hesitantly. He snuggles closer to Mycroft. He's shaking. Something pops in Mycroft's ears. His dick gives a mighty lurch; he can feel the pre-come blurting out.

Christ.

Mycroft tries to fight it. He lasts a few seconds. It's too strong, too big, that calling and Mycroft is intoxicated by Omega Pheromones.

"Yes. Omega's first heats last a long time." His voice has taken on a scholarly tone without his conscious consent, dry and a bit condescending. He firms his arms around Sherlock.

"It takes time for your body to be ready for the Alpha knot." Mycroft is watching Sherlock. _Bullshit. With a few fingers first, Sherlock could take him right now_. _Maybe even without._

Mycroft's words affect Sherlock. He sees his pupils dilate, hears the catch in his breath.

"I'm sorry." Mycroft says, stroking Sherlock's cheek with a thumb. _Liar_.

"I'll help you wait." He promises, feeling a dizzy elation at the words. Sherlock moans at that, throaty and sinful. Mycroft's dick pounds.

"I won't hurt you." He adds vehemently, and _that_ at least is the truth.

Sherlock nods, sharp understanding like a wave in his grey eyes before they go all fuzzy and adoring. Mycroft's insides clench.

"How... How long?" Sherlock asks tugging at his bottom lip with straight white teeth.

He takes his hand off his erection, deliberately, instead curling both fists into Mycroft's shirt.

Mycroft can't breathe.

"Hours." He grates. _Liar_.

Sherlock shudders delicately, sinking into his role.

"And mine is just starting?" He squeaks. _Liar. Sherlock has been in heat for over a day. It's a miracle he's still able to talk._

Mycroft gulps.

Nods red-faced.

Wrong, wrong, so wrong yet so RIGHT. What should have been, years ago.

Sherlock makes a little whimpering noise Mycroft has never heard before. He squeezes himself to Mycroft's chest, hugging like a bur.

"It's okay." Mycroft says. "I'm here."

For a while his brother just trembles in his arms. His hands twitch in Mycroft's pricey shirt and Mycroft knows Sherlock is resisting stroking anywhere that will relieve either of them.

He can do this. If Sherlock can tolerate heat, Mycroft will keep his knot under control.

"Do you know what happens to an Omega's body during heat?" Mycroft asks, somehow making his voice strong and confident.

Sherlock _hmms_ which could mean anything.

"Your body will produce a lot of hormones. It will feel like a fever. Your body will be getting ready for pregnancy."

Sherlock gasps in shock. Mycroft hushes him.

"It doesn't happen anymore. A long time ago, Omegas could birth babies. Evolution has changed that, but your body will still try."

Sherlock relaxes.

Mycroft kisses the top of his head.

"Your opening will get ready for an Alpha knot. It will loosen and grow blood-engorged and very sensitive." Mycroft should feel ridiculous preaching like this, but instead he is more aroused than he's ever been. Sherlock is hanging onto every word.

"Your body will produce secretions so I don't hurt you. You might leak a bit later." _Liar. Mycroft can smell Sherlock's slick right this minute._

 _"_ You might get an erection." he confides. Sherlock groans and shifts at the reminder of how his dick desperately needs contact. Mycroft's hurts too.

Mycroft is light-headed. Sherlock absorbs the information quietly, like he always did. He is scenting Mycroft without meaning to, his nose teasing along his brother's collar.

Mycroft tolerates it as long as he can.

"Do you want me to check your progress?" He asks quietly. _God, he can't wait to see Sherlock. To touch, to smell. Omega. Heat._ His inner Alpha is plagued with a hard-on as bad as Mycroft's, and it doesn't know what to do about it.

Mycroft waits as Sherlock debates.

Finally, Sherlock pulls away.

"No." He says shyly, voice small. "Not yet."

Mycroft's Alpha growls at the nonsense. _Sherlock is ready now and Mycroft will have him_. Mycroft takes a breath. Inhales more Omega heat pheromones that drive him crazy. He can't... His Alpha struggles to take over. Mycroft needs air, needs to get out of the room, he can't...

He smiles tensely, trying to be reassuring.

"How about a walk then, to help things progress?" Mycroft proposes.

Sherlock stares at him in pure wonder. His admiration makes a warm yellow glow ooze through Mycroft's chest cavity.

 _Strong_. Alpha.

He preens.

"Yes!" His omega agrees breathlessly.

His omega.

Sherlock.

They are doing this.

...


	5. In the Garden

_Carry on, if you are an adult!_

* * *

Sherlock has agreed to take a walk with Mycroft before they relieve his heat.

The dark _thing_ in Mycroft has curled deep in his belly, satisfied and heavy.

 _Watching_.

Sherlock gets up heavily from the couch and oh, for a vertiginous moment Mycroft wonders if it's too late. Sherlock stands, bent over with his hands on his knees and his face dark. His nostrils flare in irritation at his transport.

Mycroft has to help him walk; Sherlock really is that far into heat.

Mycroft can't imagine the stubborness his brother possesses, to force his body to move when it is in such a state.

Sherlock's hips twist, _the friction of his ass-cheeks must be excrutiating_ ; it causes a stilted, oddly sensuous gait that has Mycroft positively aching.

Sherlock huffs, but he doesn't actually complain, holding Mycroft's hand in a sweaty palm.

It seems to get easier once they are in motion.

Sherlock is steadier; he pulls Mycroft along and a huge smile splits his face at the sight of the green outdoors. There is a path right to the door-step; it meanders off through the gardens, winding between hedges. The sun blinds them momentarily when they step out, creating dancing purple spots on their retinas. A bird chirps somewhere nearby.

Sherlock looks around, drinking in the familiar sights as though fascinated by everything; he seems excited like he used to be when he was younger. Always into mischief, grass-stained and muddy with twigs in his hair; Sherlock loved the garden. He spent entire days poking at the soil and gathering leaf specimens, bent on discovering every last secret of nature.

Mycroft remembers. He inhales deeply; earth and sun-baked grass. Sherlock squeezes his hand tightly, then he lets go to trot off with a whoop.

A few yards later, a cramp hits him.

Sherlock goes red in the face, looking wildly around him. His knees want to buckle as he presses a hand low to his pubic bone.

Fuck. He is outdoors in the middle of a pathway. He refuses to drop to the dirt. Sherlock bites his lip, stifling a moan. Something inside him rolls, an unnatural _twisting_ in his gut that takes his breath away. His asshole throbs, like his finger did that time he caught it in the door. His abdomen is becoming rock-hard, a slow tension that rises and rises; up to his navel, higher, spreading around his sides and down the insides of his thighs.

Then Mycroft is there, warm and solid. He steps close, encourages Sherlock to sling his elbows over his strong shoulders. Mycroft easily supports Sherlock's weight as he gratefully sags, all of his attention turned to his lower half.

Mycroft shushes Sherlock automatically; meaningless words. He swallows at how Sherlock's pelvis jerks, trying to relieve the ache. _Not only in his ass then._

The heat is now further along than simple anal lubrication; the burn and wetness in Sherlock's ass pales in comparison to the pain of his body trying to rearrange his organs.

He knows most Omega's don't experience this; they relieve the heat at the beginning. _Good little Omegas_. Sherlock isn't good. He doesn't even want to be Omega. It feels right for his first heat to be painful. A rite of passage.

Stupid _wrong_ Omega body.

Good little Omegas take care of themselves; they do not allow the hormones to reach that critical threshold Sherlock has passed. Evolution has changed Omega bodies; in a few centuries, the transition stage of heat probably won't exist anymore. It's entirely Sherlock's fault he's going through with it; it's what he gets for waiting too long. _Right_. He has awakened a deep deep drive; his body is trying to dilate his vestigial uterine cervix, to ready him for bearing a child.

Stupid. But helpful too.

The pain distracts Sherlock from the urge to be fucked. It helps if he hangs off his brother, spreading his knees into an awkward squat.

When it's over, Mycroft frets. He has fuzzy knowledge of what happens to omegas who suffer transition. Severe abdominal pain. Delirium. Dehydration. Mycroft worries; he tries to turn Sherlock around and get him back inside. _Knot him._

Sherlock shakes his head in adamnant refusal. He is so enticing like this, with his cheeks ruddy and his hair all wind-blown... Little Sherlock, all grown up. _Omega. Protect. My Omega._

Mycroft can't resist his little brother's pleading. He resisted too long, forever; today he means to indulge him, gorge on defying conventions. _Right_. For them.

So Mycroft lets himself be pulled down the path by a grinning Sherlock. Further and further from the safety of the house.

They will _have_ to control themselves now; they can't simply fuck in the garden, even if they hedges are high and keep them mostly out of sight of the neighbors.

Mycroft does not know how long their walk lasts.

It is a lot like labor, he reflects. Quiet stretches of peaceful wandering, _together_ , then bouts of intense abdominal contraction that are slowly taking their toll. _Sherlock, coming of age._ He certainly isn't complaining about having to endure his Omega body's demands, even if the sounds that do escape him are positively sinful.

Mycroft can almost understand why he is putting himself through this. It is a way to punish his body, ignoring his Omega needs.

So Sherlock...

First heat...

As long as Sherlock is not in real danger, Mycroft resolves to do this his way.

After a while, Sherlock can barely walk; he waddles along uncomfortably.

Surprisingly, Mycroft is no longer having to pretend. The urge to _mount, knot, RIGHT NOW_ is muted. Now that Sherlock is in transition, he is in actual pain. Mycroft's Alpha realizes it, and for some reason it also aknowledges the backyard is not the right place to knot.

 _Nest_.

Mycroft's Alpha sniffs around in the corners of Mycroft's mind. It does not, _can not,_ understand this omega's behavior.

Mycroft is still erect, of course. But it's fine, he can ignore his dick for now. All of his attention is focused on Sherlock, on supporting and consoling him through the waves of pain.

They find a bench and sit for a while, listening to the dry rustle of the leaves. They kiss a bit.

Sherlock grabs at his dick after a particularly bad spasm and Mycroft wordlessly takes his hand away.

Sherlock makes a hurt, frustrated noise, so Mycroft kisses his knuckles in remorse.

Sherlock smiles then, even if his eyebrows are drawn down with strain.

"Thank you." He whispers.

He shifts on the bench, hips rolling again. _Grinding. Needing to be fucked._ Mycroft swallows.

"So close." Sherlock says forlornly after a while, looking at his lap.

Mycroft looks too. He wants to bury his face there.

 _Omega. Heat._

The fidgeting continues, even if Sherlock's hands are obediently held away, arms spread wide along the low back-rest of the wrought-iron bench. Mycroft thinks he sees a small dark spot where the head of Sherlock's dick pushes against his trousers.

"I could finish." Sherlock murmurs a few minutes later in that same too-calm voice. Mycroft nuzzles his neck, overheating.

Sherlock grips his knees. His ribs move with his breaths. Abdominal contraction. When it is over, Sherlock places his arms back into their previous position, clutching the back-rest.

"Oh." Sherlock's teeth are making white indents in his lip. Mycroft watches him, light-headed with perverted fascination.

"I'm going to cum, it's not going away, god-duh." Sherlock leans back, head tipped up on his long neck. The underside of his jaw is sharp; his adam's apple bobs as he swallows. His hips fuck upwards, choppy useless thrusts. Mycroft is speechless.

"Ugh." Sherlock grunts. Mycroft is tormented by a terrible tension in his own crotch.

"Please." Sherlock begs.

"So bad." Sherlock's voice is barely a whisper. He is hanging on by a thread. Mycroft groans helplessly.

"Mick, I can't... It wants...Right now." Sherlock whines, and his head rises.

Then he kisses Mycroft with all that bottled up despair.

An explosion of desire crunches through Mycroft's shock-induced hesitation. He needs to help Sherlock cum.

Mycroft's large hands grip the sharp wings of his brother's hipbones, digging in.

Enough teasing, Mycroft is going to make Sherlock cum. Sherlock deduces it, reads the way Mycroft's posture stiffens.

"Hah." Sherlock gasps, wrenching away from the forbidden kiss with his mouth slack and his eyes screwed shut.

Mycroft blinks stupidly, trying to process the sudden loss. Sherlock curls into a ball, drawing his knees up with his feet flat on the hard bench. He isn't wearing shoes and his toes grip the edge.

"No, no, don't." The omega, _his omega_ , pleads shakily.

Mycroft can see the dark stain, all down the seat of Sherlock's pants.

He can't, he needs.

Sherlock needs...

Sherlock doesn't want...

Temptation. _Torture_.

Mycroft gets up to pace again.

He runs a hand through his short hair.

"I..." he starts.

His Alpha is torn; _protect-mount-nest-knot._ _ **My Omega.**_

This is unnatural. It's what Sherlock wants.

His brother's eyes are open now, brilliant and unfathomable.

He looks finally calmer. Not having Alpha scent in close proximity probably helps.

Sherlock's voice is filled-with-glass-shards rough as he admits.

"So close... God, right on the edge... For so long. I've never managed, alone."

Mycroft starts to apologize but falters under the warm blanket of Sherlock's adoring look.

"Thank you. " Sherlock finishes and that's it, he has Mycroft wrapped around his little finger again.

" ´m so hot." Sherlock whines. And... he's back in his little brother role.

 _Afraid. Dependant._ Mycroft is dizzy with lust.

He croons empty reassurance; _good boy_ and _doing so well_ and _I'm here, it's okay._

Mycroft helps Sherlock take his shirt off. His brother's fingers are awkward, fumbling buttons and his elbow gets caught in twisted fabric. Mycroft tuts and sets him right. Sherlock is panting.

Mycroft kisses the flushed skin of Sherlock's smooth chest, ignoring the peaked nipples. They are swollen and hard and Mycroft thinks neither his nor Sherlock's restraint will stand the strain if he suckles one directly. Sherlock's fingers thread through his hair as Mycroft takes his time, sinking to his knees to lick the salty sweat from his abdomen.

Mycroft's tongue laves around the cute navel; it makes Sherlock squirm and giggle so he does it again.

"Tickles." His brother protests, too high-pitched. Sherlock rubs his belly absently when Mycroft's lips leave, smearing the wet trail. He does not dip below his pants, but they are low-slung enough that a fair bit of skin tantalizes Mycroft.

"Sore?" Mycroft splays his hand over his brothers.

Their fingers are different. Sherlock's are longer, thin and graceful; a violinist's fingers. Mycroft's are thicker, the bone structure different. His nails are cut straight and pink.

Sherlock nods, looking at Mycroft with dark dark expectant eyes.

 _Omega. Heat._

Pheromones so intense there is a taste like metal in Mycroft's mouth.

Mycroft gets up, quickly evaluates their surroundings: he sits on the ground a few feet away, in the spotty shade of a huge tree. _Mycroft never sits on the ground_. It is unrefined and primitive and fuck, Sherlock is in heat.

He leans his back against the rough gnarly bark and spreads his legs, patting the ground between them. After a minute's hesitation, Sherlock lurches over and drops down into the vee.

Mycroft's shirt buttons dig into his skin; it is _unbearable_.

He jostles Sherlock who is mid-cramp again, tugging his shirt out of his pants and finally finally feeling the cool breeze on his chest.

They settle together under their tree.

Sherlock melts against him with a happy hum.

Their bare skin rubs together, back to torso and the contact appeases the Alpha somewhat. Mycroft's arms wrap naturally around his brother in this position. He is free to run his hands over all that glorious nakedness. It would be even better without their pants, but Mycroft tries not to think of that.

Sherlock leans his head dreamily back on Mycroft's shoulder and their scents mingle. _Right. My Omega._

Mycroft's hands are drawn to Sherlock's tummy, where he aches, so close to his cock. Mycroft's hand rests there, low on Sherlock' body, while both his brother's hands grip his thighs. Mycroft rubs slow circles that make Sherlock shudder, a pretense at soothing. Torture. Temptation.

Sherlock bites his lip and submits agreeably, like a good lost little brother.

Mycroft's cock is horribly hard, trapped in his pants. It grinds against Sherlock's back though, which helps take the urgency off.

Sherlock seems to enjoy the new position. He arches with his mouth open when the spasms hit, rubbing himself against Mycroft's chest hair with a crackle; he stops the cat-like motions as soon as the cramps are over. Then he goes all mellow and content; if he actually were a feline, Mycroft is sure he would be purring.

It is lovely. Knotting is an after-though, the need not so urgent as they savor the current stage of heat.

The wind is strong; it makes the long grass wave and the branches move with dim clacking sounds. Dappled green sunlight bathes them, cleanses away all the angry hurt. A bee buzzes by.

Good.

Mycroft's brother rests pliant in his arms.

They wait together him to be ready. They are lost in a shared fantasy.

 _Sherlock, Omega_. He has stopped fighting it.

Sherlock is leaking more in this embrace. Mycroft can smell it.

"So strong." Mycroft whispers. Mycroft is amazed by his beautiful Omega brother.

Then. "You're doing so good, Sherlock. I love you." Words he never dared say before, faced with cold cynical adult Shelock.

Sherlock moans and stetches a long arm up to press Mycroft's head closer to his own, crushing their cheekbones together.

Sherlock closes his eyes, lets himself be one with his omega urges. The pains are steady now. Sherlock is no longer afraid. His brother will take care of him.

"Breathe, Sherlock." He reminds him when it gets worse. "Just one more. You can do it."

His thumb pushes into Sherlock's flat belly, feels how tight and aching and hard it gets. Mycroft soothes until the cramp eases; until Sherlock is sweaty and relaxed again. _Endorphin high._

Time goes by. An hour, maybe.

Mycroft can't tell. He does not tell time in minutes. He tells time in the waves of Sherlock's heat.

Sherlock, Omega.

Eventually, Sherlock grows more agitated. He writhes, even between the cramping that is relentless now. He is more vocal, bending in half as his body takes over.

Sherlock, ready.

Mycroft wants to knot now. He can feel the blood pooling low in his belly. Their time of rest is over.

Mycrofts makes the decision to take them back inside.

Sherlock, his Omega.

...

It is almost too late. Mycroft waited too long. He had not realized how bad Sherlock's state was, lulled by how calm and _happy_ his brother was. Now, it is almost too late.

Adrenaline surges in Mycroft. He has to get them inside. It's his responsibility to ensure Sherlock's safety.

Sherlock stumbles on jelly legs, dragged by the strength of Mycroft's hand in his.

"Please." He begs breathlessly, pupils blown impossibly huge in sea-glass eyes.

 _"I can't."_ Sherlock says, and he means it.

"You have to, Sherly." Mycroft pleads. Mycroft mis-judged. He messed up.

God, he needs to get them inside.

"Come on, you can do it." He encourages, that dark _thing_ inside him squeezing squeezing his lungs.

"It's not far."

Sherlock moans, loud and wanton; he clutches a fence post, nearly dropping to his knees. Control, slipping away.

Mycroft hauls him back up before the cramp has fully dissipated; he allows more firmness to creep into his voice. He forces Sherlock back into movement, off-balance with too-long strides when all Sherlock's body wants to do is present on all fours.

 _Sherlock, in heat._

Fuck _._

Mycroft manages to get Sherlock inside by sheer force of will; fully utilizing the inexplicable mix of bullying and coaxing only a brother can wield.

Inside. The door slams.

Finally safe.

...


	6. Bathtubs and Bedrooms

The house is quiet; it's shadowy interior is soothing.

Sherlock sags against the door gratefully. His hair is plastered to his head with sweat and his face shines, but he looks more put together than a few seconds ago.

"I'll get you some water." Mycroft says.

Sherlock shakes his head.

Mycroft rubs his shoulder.

"You need it." _Delirium. Dehydration._

Sherlock admits quietly, staring at his shoes. "I have to pee. Real bad."

Oh.

Mycroft can feel his ears turn red, awash with tenderness for his shy brother. He solicitously ushers him to the washroom, gently admonishing him for not speaking earlier. Sherlock stand awkwardly in the loo, hands wringing together as he waits for his big brother to get out.

The door closes with a clack.

Mycroft leans against the wall, finally alone. He palms his cock vigourously, fingers working over his zipper. It is a relief to finally be able to touch himself, but it is not nearly enough.

If Mycroft took his pants off, he would come in seconds.

He runs a hand over his stomach instead, shivering as the sweat dries. He feels the softness at his middle, so unlike Sherlock. Mycroft is not fat, not anymore, but no matter how he pushes himself on the threadmill he can never get rid of the pillowiness. He _hates_ it.

He remembers Sherlock, a cubist collage of hard angles that somehow work; jutting hip-bones and concave mid-section, sharp nose and too-flat cheek-bones. Mycroft knows the truth now. Sherlock's firm transport is not healthier than Mycroft's detested softness; it is born from drug addiction and disregard for his basic needs.

Mycroft used to be bitterly jealous of how his brother nonchalantly flaunted his lanky physique. Now he knows how much Sherlock hated it; how he fought against his own body day after day.

Bodies.

Just bodies.

Transport.

An Alpha.

An Omega.

An Alpha in an Omega mold.

Transport.

The realization casts a strange green glow on Mycroft's perception of beauty, coloring the ideals he so aspired to reach. He will need to reflect on the matter. Later.

"Mycroft?" Sherlock's voice wavers through the bath-room door and Mycroft instantly jerks to attention.

"Yes. I'm here." He says, keeping the panic of his rabbit-heart out of his voice.

No answer.

"Sherlock?" Still no answer. Fuck.

"I'm coming in!" Mycroft announces, turning the handle. He really hopes Sherlock didn't lock it.

It opens easily and Mycroft's bursts into the room with undignified haste.

Oh god. _The smell._

Mycroft groans and bumps into the counter-top as his Alpha _roars_ inside.

 _Omega- heat-mine._ _ **Knot knot knot knot knot knot knot.**_

He takes in the sight of Sherlock, who seems unharmed.

His brother stands in front of the toilet, caught in Mycroft's wild stare.

"I, Mick, I just..." Sherlock's voice is too weak, too uncertain.

The dark thing rears up too, fights the Alpha for control. Mycroft knows Sherlock is acting on purpose, playing on his sensibilities to force Mycroft to behave.

The dark thing absorbs the light, forces the Alpha back into a corner panting.

Sherlock is holding his undone pants up with one hand. The other presses to his delicate throat.

He blinks, slowly. God.

Sherlock blushes, looking at the floor. Mycroft wants to hold him again. The Alpha recedes grudgingly.

"I thought you might check my progress." Sherlock mumbles too fast.

Mycroft swallows. He needs to be strong; needs to be a good sibling and think of his brother first.

"Okay." He answers, room swaying in his peripheral vision as he heads foreward.

 _Omega. Heat. Mine_. Finally.

He runs a hand down Sherlock's back and his brother stays quiet. Sherlock bends forward, grabbing the cistern lid with both hands and dropping his ruined pants to puddle at his ankles. As an after-though, he steps out of them, the motions making his ass flex. God it _shines_ with slick, all down the back of his thighs too.

Don't. _Control_. Strong.

Maybe Sherlock isn't ready for a huge cock. Omega's first heats are long. Sherlock is a virgin. Mycroft clings to the fantasy; the net of whispy lies just barely holds him in check.

Mycroft places a hand on Sherlock's ass cheek. Wonders at that smooth smooth skin. Does Sherlock shave? Probably not. Mycroft remembers lack of body-hair is an omega trait, one probably evolved to drive Alpha's _crazy_. All that glorious unblemished skin makes Mycroft want to lick and mark and rub his face all over and _no_.

He needs to check Sherlock's progress.

"Okay." Mycroft says again, fascinated by the evidence of how aroused Sherlock is. His body is telling a different story than his face is. _Masks. Lies._

Mycroft kisses Sherlock's shoulder-blade without thinking, sliding his index finger directly into Sherlock's ass crack. It goes in like butter and _oh goodness, so hot_ and _wet_ and the _sound_ Sherlock makes... Such an indecent moan; it makes Mycroft's toes curl.

Mycroft stills his finger, doesn't fuck Sherlock like the Alpha wants him to. He pauses, takes a shaky breath; control like a sheet of tissue paper in the wind. The world grinds to a halt, narrows to the over-bright sensation of Sherlock's slipperiness smearing over the rest of Mycroft's hand.

Sherlock's head hangs and he is gripping the toilet desperately. When Mycrofts looks down over his brother's trembling shoulder, he can see the angry red omega cock bobbing.

Sherlock is losing it. He tries to back up on Mycroft's finger; his spine curls so his ass turns up. Mycroft can feel his inner mucles gripping and releasing, trying to milk his finger.

 _Omega_. No. Wait.

Mycroft groans, digs the fingers of his other hand into the muscle of Sherlock's ass as he pulls his index from the warm hole.

Angry red finger marks form on pale white flesh. Probably, they will bruise.

Mycroft isn't sorry.

 _Mine_.

Sherlock lets out a sob at the loss of penetration, humping air.

Sherlock hurts. Sherlock is in heat.

Mycroft hurts. His hand goes to his dick and he squeezes.

He wants. God, he wants.

Sherlock wants.

Sherlock is ruled by biological impulse at the moment. It isn't what he _really_ wants.

 **KNOT**.

Mycroft can't fucking _think_.

Mycroft waits; a minute, an hour, a lifetime.

Until Sherlock quiets a bit; inhales rough, loud in the small bathroom.

Mycroft swallows thickly. He will deny them, once; offer Sherlock one last chance to pursue his fantasy. Then he will **KNOT**.

"Sherly." Mycroft kisses that sharp shoulder-blade. He digs into himself, finds his concerned big brother voice despite the ringing in his ears.

"Sherly, I'm sorry." He adresses his little brother. "I know that hurt." _Liar_.

"I'm sorry."

Sherlock grunts. Mycroft is not sure he understands words anymore, his heat too strong.

One last chance. Before he **KNOTS**.

"I'm going to try again, ok, Sherlock?" Mycroft says.

His dicks kick so hard at his next words that they come out strange and flat.

"Try not to clench so hard. I know it's weird and uncomfortable." _Liar_. _Liar. Liar._

"But you have to let my finger in. I need to check how far along your heat is. First heats are so long and I promise not to hurt you. I swear, Sherlock, I... I can control my knot. But we need to know..." Mycroft is babbling and he stops himself.

Mycroft's breath won't seem to get into his lungs.

 _Ripe Omega pheromones._ This is the last chance.

 **KNOT**.

Mycroft takes his time, as much as he can.

He lets Sherlock feel his hands on his ass.

Mycroft spreads his brother and indulges; he allows himself to really look at the pornographic sight of Sherlock's body in heat. He groans; Sherlock's hole is puffy and glistening. As Mycroft watches, it winks, searching for friction; a drip of clear fluid seeps out. _God that's hot._ Mycroft wants to taste.

Instead, Mycroft slowly, methodically, drags his finger down through the slipperiness.

He stops with his index just on top of the orifice; feels it pulse with rythmic greedy need. _Torture. Temptation_.

"Don't clench." Mycroft warns again through gritted teeth.

He holds his breath and pushes his finger in. It sinks effortlessly into the swollen gland. Mycroft's Alpha sags in relief. **KNOT**.

Then, inside, there is resistance.

Unbelievably, the second ring of muscle is tight. Mycroft probes a tiny bit. The resistance does not let up, although Sherlock makes a noise like he's dying. Mycroft can't get his finger further.

Omega.

Not ready.

Mycroft's heart splits in two; sinking into a deep canyon of frustrated despair while simultaneously launching into the stratosphere with elation.

His amazing, brilliant brother. They are going to continue this twisted fantasy for a bit.

 _Too tight. Not ready_. Mycroft promised...

Even in such an advanced stage of heat, Sherlock understood the double meaning.

 _Don't clench._

 _Don't._

 _Clench._

 _D..._

 _Clench._

Mycroft wasn't sure Sherlock would get it, or that it was what he wanted or even that he would be able to physically tighten down there. He would have fucked him gladly if Sherlock had been ready. His Alpha digs at the ground with a hind paw, tail lashing.

Mycroft does not linger and pulls his finger out; he watches a veritable flow of lubrication follow it as Sherlock's hole gapes in relief.

Sherlock sinks to sit on the toilet seat, backwards with his long legs splayed and his forehead on the cold reservoir.

"Well?" He asks in broken whisper.

Mycroft clucks; he runs his hand through Sherlock's sweaty hair, scratching at his nape to watch the goosebumps spread.

"Not ready." He says, voice glowing with disappointment.

"Sorry." He feels compelled to add, even if Sherlock was pushing him away on purpose. They are back to their rightful roles; helpful big brother and tormented little Sherlock, waiting waiting waiting for his body to be ready.

Sherlock stays where he is and Mycroft wonders from his breathing if he's crying. Maybe.

"There is engorgement." he reassures.

"And a bit of slick." A blob of Sherlock's thick fluids drops into the toilet with a plop then. Mycroft falters.

"You're just too tight still." _Liar. Torture._

Sherlock doesn't answer. Mycroft thinks he's pouting, like he did when he was five and things didn't go his way.

Mycroft needs to find a distraction, because his restraint is slipping away. He can't keep his hands off Sherlock. Soon he will be back to the genitals where Sherlock he is all too tempting.

 _Knot, knot MOUNT; Mine._

Taking inspiration from the pseudo-labor aspect of transitional heat, Mycrofts says the first thing that comes to mind.

"How about a bath?" He inquires.

He thinks Sherlock is too far gone to understand, but after a minute he answers weakly.

"Yes."

A bath. Good. It gives Mycroft purpose. He can prepare a bath.

Mycroft busies himself with the taps, listens to the old pipes clang.

"Not too hot." Sherlock says, face still hidden. He sounds so tired.

Mycroft sets the water to lukewarm, colder than he would like personally but he is not the one in heat.

"Up you go!" he says, when the bath-tub is full.

Sherlock is agreeable enough, struggling to his feet and leaning on Mycroft before clambering over the side and dropping heavily into the water with a splash.

He looks high, _fucking wasted_ , eyes dilated and body gangly.

Mycroft gets up; he cracks the door a bit. He can't stand the concentrated omega scent when faced with all that wet nakedness.

"Don't go." Sherlock pleads, lips cracked.

Mycroft reassures him; he finds a little bench that he drags by the head of the bath and sits on it. He remembers that bench. He remembers helping little Sherlock climb up to brush his teeth, chubby fingers awkward on the too big toothbrush. Mycroft can't believe Mummy kept it all these years.

The bench is too low and Mycroft grips the edge, white-knuckled. He widens his knees, trying to get comfortable. That is how he finds out he can rub his erection against his fore-arm; little furtive motions that maybe help the ache of denial a bit.

Humping.

Bestial.

Mycroft is ashamed but he can't make himself fucking stop.

Sherlock is watching him with slitted eyes, but he does not comment.

"This is nice." Sherlock breathes. He is visibly more relaxed, floating in the water with his knees sticking up pointy, _too long legs like a grasshopper._

Sherlock closes his eyes, _dark slash of fuzzy eyelashes_ ; he hooks his neck over the edge of the tub and rests his arms along the sides of the ancient claw-foot. His pelvis is suspended, bobbing in the water. The smell of slick is muted by the liquid too, and Mycroft can breathe without choking on Alpha instincts.

Sherlock does not seem as bothered by the cramps in the tub. Mycroft can tell when the heat peaks because his brother's face gets more _intense._ Those slender musician hands grip the rim of the tub tightly.

From his position by Sherlock's head, Mycroft looks down his body; he can actually _see_ his omega's abs clenching with the heat. Sherlock bites his lip, hips curling up. His legs move uncomfortably; the water makes soft lapping noises in waves against the enameled sides of the bath before he relaxes.

Sherlock's dick is impossibly hard, bobbing in the water. Mycroft wants to suck it.

He doesn't. Now is a time for him to take a step back, to observe.

Sherlock is entirely focused on his body, and he is handling the heat exceptionnally well.

Sherlock seems to be concentrating in a bubble of his own creation, and Mycroft doesn't touch him. He sits on his hard bench, crooning nonsense and perpetually amazed by his brother. So strong.

Time grows molasses slow and bitter-sweet again.

Sherlock.

Omega.

Soon he will be ready for Mycroft.

...

Much much later it feels, _an interminable lifetime of waiting later,_ Sherlock is starting to grow more distressed. He is vocal again, shifting roughly and nearly making the water spill. He looks straight at Mycroft, panic in his eyes. His breath is short and too fast.

It is Mycroft's turn to be strong.

"Time to get out!" he announces, keeping his voice firm. The respite has helped him. Mycroft feels in control. He can think.

Sherlock nods, chewing on his bottom lip again. His lip is red and swollen,

Mycroft jumps when Sherlock suddenly disappears, sinking into the water. It gives him a fright to see black hair floating like lifeless seaweed on the water.

Then Sherlock sits up, streaming water and wiping his face and ok, _he's ok._

Mycroft finds a large towel that smells comfortingly of clean laundry.

Sherlock is docile, dripping water onto the mat. He lets Mycroft scrub him dry, even if the texture of the towel is surely scratchy against his over-sensitized skin. Mycroft wraps the cloth around Sherlock's shoulders; he rubs up-and-down over his brother's biceps then vigourously musses inky curls. The pattern is familiar, soothing; Mycroft is acting on pure muscle-memory. He used to take Sherlock from the bath almost daily, since Mummy hated getting wet on her clothes. Except back then, his little brother used to squeal and wiggle, fighting Mycroft's capable hold. Sometimes, he managed to slip away stark naked and run furiously through the house, bare-feet slapping hardwood till Father intervened.

Today, Sherlock is too quiet, listening to the water gurgle as the tub drains.

He is sick.

He is in First Heat.

Mycroft must take care of him.

...

They head to Sherlock's bedroom, and Mycroft finally shucks his pants. They are unbearable.

The afternoon air whispers over his naked body; the relief is so intense he can't suppress a moan.

KNOT.

Sherlock is waiting on all fours on the bed; Omega. Heat.

Sherlock's body curves in such beautiful lines Mycroft wishes he could paint that upturned ass, swathed in the fuzzy golden light of the diminishing afternoon sun. He settles for comitting the image to photographic memory, to be cherished and fondled forever.

Mycroft positions himself behind his brother. MOUNT.

"Ready?" He exhales.

"Check me first please." Sherlock begs.

Mycroft grunts. Fuck. He does not remind Sherlock not to clench; he is ready to take his Omega NOW. Mycroft's dick-head hurts, leaking more pre-cum than he has ever seen. It is ridiculous.

Sherlock mewls when Mycroft's finger, slow and deliberate, enters him. It is dryer than before, the slick washed away by the bathwater.

Sherlock arches decadently.

Mycroft swears under his breath.

Still tight, _too tight,_ god damn it. He won't hurt Sherlock.

Mycroft can't wait anymore. He can't.

He pulls his finger out and sucks it absently.

"So?" Sherlock's haunting eyes are watching Mycroft's struggle over his shoulder. There is a look of triumph on his face.

Mycroft gulps, again.

He can't speak, trapped in their fantasy. Too much, too long, he can't... Mycroft wars with his body, with his Alpha that is trying to force a Merge, something it has never done before.

Finally, he gains control.

"Progress." He says in a deep voice he doesn't recognize. Like Lestrade when he'd merged earlier. The Alpha, so close to the surface... Sherlock shudders at the sound.

Mycroft traces Sherlock's flank, the muscles moving, _alive_ , with breathing and rythmic helpless rocking.

"I got a finger in." _Even if you were trying with all your might to hold it out._ He does not add.

"Tight." Mycroft admits. "But getting there. Soon you'll open up more and you'll be ready for my cock."

Mycroft holds himself by the base, sorta waves his erection at his Omega. _Instinct_.

"Aurgghh!" Sherlock rolls to his side. He unravels before Mycroft's hungry eyes, clutching his small dick. The last of his resistance went into that final clench.

"It takes so long." Sherlock babbles. He tries to rub against the bed, hips moving in slow circles.

"Please, Mycroft." He says. Mycroft's balls ache. Sherlock is _writhing_. It is indecent. Omega. Heat.

"It hurts. I can't wait any longer." Sherlock pushes the clingy bangs from his face, unable to be still.

Mycroft shakes his head, a fizzing rush of power through his veins when Sherlock's face falls at the silent refusal.

"Oh. Oh." Sherlock reaches a pleading hand towards his brother, lets it fall to the white sheet without touching him.

He does not touch himself either though, not his ass nor his penis, so some part of Mycroft realizes Sherlock is enjoying the apparent loss of control as much as he is.

"Please. Mycroft. Please. God, I need." There is awe in Sherlock's voice. All his words are seperate sentences, half-formed pleas seperated by breathy moans and lustful rolling.

Sherlock is beautiful in abandon.

Mycroft watches until Sherlock's begging grows earnest, an edge of raw desperation spiking the words.

Mycroft kneels over Sherlock, jerking off slowly. Sherlock's eyes are mesmerized, fixed on Mycroft's large Alpha cock. He has never felt so strong and powerful as he does now, engorged to the limit with a prominent vein twisting down the shaft. It is difficult to still his hand, to hold himself in a virile display that has Sherlock on all fours again.

"I'm too big." Mycroft says. "I'll hurt you."

Sherlock shivers.

"I don't care." He says defiantly. _Little Sherlock with his chin raised, ignoring the rules._

"Do it. I... Do it." _Flashback_. Sherlock is shaking, his brother can hear the worry masked by bravado.

Mycroft kisses Sherlock's neck, trailing hot breath down his back.

"Shhhh." He soothes.

"You can wait. I'm there. Just a bit longer." he coaxes. Sherlock's eyes are black, huge and trusting.

 _Masks_.

Burned to ashes.

Sherlock nods bravely.

Sherlock's body won't stop moving now.

He is leaking, leaking, leaking. Mycroft is burning, burning, burning.

Time is strange.

They spend a while on their sides with Mycroft hugged to Sherlock's back, until the proximity of his dick to Sherlock's needy core gets too much. Mycroft can't bear it one second more, he will shove it in.

He sits cross-legged by his brother.

Mycroft spends a long time stroking useless circles on Sherlock's skin, rubbing his tummy like Mummy did when they were little and sick. He can not tell if it helps or makes things worse anymore.

Sherlock's eyes are closed and he makes noise constantly. There are no more visibly seperate cramps; just the impossible, never-ending slow surge of the heat now.

Water, seeping into the glass box of their fantasy; the level rises steadily as a trickle slowly fills every corner of a glass box. Inexorable. Soon, a tiny crack will give from the pressure; a stress fracture in either Sherlock or Mycroft that will topple them from this heady plateau.

Sherlock is soaked in sweat. So is Mycroft.

Eventually, Sherlock begs Mycroft to check him again.

He does, fully expecting to finally feel how gaping his brother is.

Instead, Sherlock tortures them, clenching stubbornly so that Mycroft gets only one finger in. He is looser than before though. Maybe Mycroft could fit a second one, if he works it. _Maybe he could fit his cock in, if Sherlock stopped fighting._

Mycroft never wants Sherlock's heat to end. His Alpha has given up; it whimpers and paces, stamping it's hind legs to try to relieve the ache of constant erection.

Mycroft takes his probing finger out immediately; he does not dare to leave it longer than a few seconds. Sherlock is already grunting with pained exertion.

Mycroft thinks he might cry in frustration.

Reality and fantasy are all muddled. _Not ready._ Wait. He won't hurt his brother, he will keep his promise.

Sherlock doesn't respond when Mycroft shakes his head.

Sherlock is delirious, almost. He rolls to all fours, burying his face in the sheets. He keeps presenting, so inviting; his lean thighs are wide and his fists grip the sheets.

He mewls pitifully and Mycroft can't resist looking at his hole again; god. He's going to rim him.

Sherlock bolts away the minute Mycroft's tongue touches him, _no no no_ , but his hand clutches his dick and he jerks off in rapid pumps.

Mycroft wants to suck him.

"Lemme suck you." he asks, or maybe commands, in a throaty rush.

Sherlock moans and nods.

He settles on his back. Mycroft dives for his brother's dick greedily, barely taking the time to situate himself properly. Sherlock's dick is a typical Omega's, small compared to an Alpha's but so agressively hard.

Mycroft swallows it inelegantly down to the root, closes his lips tight. God, the taste! Pure Sherlock.

Mycroft's Alpha lunges forth to take the lead. Mycroft lets it.

He sucks, slurping saliva all over his chin. He wants more; wants to feel the organ twitch on his tongue and taste his brother's cum.

Mycroft moves his head up and down.

Sherlocks SHOUTS, arching off the bed. His hands lock onto the sides of Mycroft's skull. Mycroft squints, tries to see his brother's face when Sherlock abruptly goes quiet, convulsing rigidly as he spurts again and again into his brother's mouth.

Oh lord, the taste. The taste of Sherlock's ejaculate is even better than the pre-cum. Primal and thick.

Mycroft's Alpha wants more, wants to roll in the pheromones and _bathe_ in the scent.

Mycroft swallows all the semen;he laps at Sherlock's cock gently as his brother recovers from the orgasm.

It's not enough to satisfy the heat.

It won't be enough, they both know it but for a few minutes the urgency is lulled.

Sherlock looks relieved. Calmer.

His cock never goes down, of course it doesn't, but there is clarity in his eyes.

He does not ask Mycroft to check him again. The ejaculation has washed away his control. Riding the hormonal high, it is impossible for him to clench again. His body has taken over.

Instead, Sherlock rises to his knees.

"You turn..." he whispers.

His turn? Mycroft is stupid, bogged down with lust. He lets himself be placed as Sherlock wishes it, on his back. His Alpha thinks, _hopes_ , that Sherlock will sit on his dick. Not as good as other positions but by this point Mycroft's Alpha will take anything.

"Yes." Sherlock says.

"Time to prepare your knot." And oh, he is _evil_.

As his dark head bends to suck at his Alpha's dick, part of Mycroft is complaining.

Nonononono.

Alphas don't knot before fucking the Omega!

Sensations tear through Mycroft and he groans, knocking his head against the pillow. Sherlock possesses the finesse of long experience at oral sex that Mycroft didn't. He manages to take an impressive amount of Alpha cock, hardly choking.

Sherlock sucks and his long fingers work the base of Mycroft's dick, fondling his balls. Sherlock does a _thing_ with his tongue, almost a flutter, right at a sensitive spot Mycroft didn't even know he had and it makes Mycroft see stars.

So good. Mycroft can feel Sherlock's tongue and yes, fuck, _his throat_ , work as he swallows.

Mycroft doesn't know what sounds he makes. There is a sponginess near the base of his cock, where he will knot. Of course, it isn't engorged fully yet! That's just impossible, even if Mycroft is out of his mind from Sherlock's expert blow-job.

Sherlock coos in disappointment when Mycroft fails to inflate, tries harder. His brother can only blink at him, air whizzing through his nose desperately.

Sherlock reaches behind himself; he works a hand into his own ass crack. There is nothing staged or enticing about the action. Mycroft winces. It's so real, _too real_ , efficient, like Sherlock must look like when he wipes after using the toilet. Mycroft's face pinches in embarassement.

Sherlock's hand is glistening with slick when he puts it back on Mycroft's genital. His long wet fingers squeeze and massage, mostly around the base Mycroft's dick and ugh.

Mycroft feels the tingle start, the one that starts the knotting.

Of course, omega pheromones... Fuck.

Mycroft gasps.

"Let it happen." Sherlock instructs. "Knot, Brother."

Mycroft moans as blood starts to pool in his groin and does his best to relax.

Sherlock is looking intently at his face and Mycroft can not guess what his Omega sees.

He is bare, raw.

Sherlock kisses him, madly, and Mycroft responds with slack lips.

Sherlock's hand continues to work his dick until Mycroft half-knots, whimpering as he pulses.

It's uncomfortable and _wrong_ , without an omega channel, and Mycroft weakly pushes Sherlock away.

Torture.

"Now?" Sherlock asks while Mycroft is still trying to gather his wits.

Temptation.

"Fuck me, brother." Sherlock says seriously. The moment shimmers with intensity.

Mycroft groans. His Alpha roars.

Faster than he would have thought possible, Mycroft flips their position.

Sherlock ends up on all fours like earlier, whining into the pillow.

This time, Mycroft rises confidently onto his knees and sinks his dick right into the omega's ass. Enough teasing.

There is a brief moment of resistance when Mycroft's knot, swollen to more than twice it's usual size, presses against the rim of Sherlock's hole. Except for hours of teasing, Sherlock has not been properly stretched; Mycroft does not even know if it's physically possible for an Omega to take a knot on the first stroke.

Mycroft's Alpha takes over, using both hands to spread Sherlock's asscheeks; he bends forward over his omega's ass and rises straighter on his knees, _god Sherlock is tall._ A nudge with his knot, then a wiggle just so and Mycroft is in.

He bottoms out, knot pushing passed Sherlock's rim.

Sherlock HOWLS. Then he shakes and abruptly cums, spurting untouched all over the bedding below him.

It all happens so fast, Mycroft's mind hasn't caught up.

He hasn't cum. Yet.

But he is _in_ , knotted with his omega brother.

Finally.

He tries to give Sherlock a moment to recuperate, but the urge is too strong. Instinct takes over and Mycroft thrusts. He can't really fuck, knotted as they are. But he rolls his hips, grunting and jostles Sherlock's body. His knot swells even more and for once the Alpha agrees with him.

Knot.

Mount.

It does not want to cum yet either; it wants to enjoy the pretty omega.

Mycroft grinds into Sherlock until his brother's arms give out; Sherlock's chest is flat on the bed, red-face turned unseeing to the side with his ass up like a good little Omega.

Relief.

Finally.

Soooo Goooood.

Mycroft's knot feels huge, and it must be pressing against Sherlock's prostate because he leaks continuously. With every deep roll of Mycroft's hips, fluid streaks out of Sherlock's hanging dick. He takes himself in hand and Mycroft licks at his spine as he continues the choppy strokes.

Omega.

Mine.

Intense pleasure that crackles through every nerve-ending.

Sherlock is making little forced noises, _ha, hargh, ha, ha, Myc, ah,_ with every move.

His hands slows on his dick for a stroke, two and NO. Mycroft pushes himself deeper, draping himself over Sherlock; he is going to make him cum. No more denial.

Sherlock keens. Then his body siezes again.

Omega.

Mine.

Sherlock's orgasm makes his channel contract around Mycroft and that does it.

Without warning, Mycroft is cumming and cumming and cumming. He empties and empties and empties his pent-up seed into his brother, grunting hoarsely.

Sherlock mewls again and Mycroft think maybe he cums too, but his ears are rushing too much to hear and his heart is racing, racing, racing, hard irregular thuds; he is close to whiting out.

Relief slowly follows the thunderous pleasure, making Mycroft weak and trembly.

He sinks onto his side, taking Sherlock with him, trying to catch his breath. His mind is reeling from how fast it all ended. They are stilk knotted, and they have to wiggle around to find a comfortable position.

Still knotted and Mycroft never wants to let go.

My Omega.

Soon, they will start again.

Heat.

Sherlock's relieved breaths turn hicuppy and he presses a limp hand to his face.

Mycroft goes on alert.

"Sherly?" He asks.

Sherlock's voice vibrates too much when he answers. "I think I might cry a bit."

And he does, and Mycroft holds him in his arms, only this time they are firmly knotted.

Tied together.

"Better?" He asks when Sherlock quiets.

Sherlock sniffs and nods.

"I'm Omega." He whispers.

Mycroft wants to answer, but he doesn't know the right answer. He can't tell what Sherlock needs to hear right now.

Alpha.

Omega.

Trans-gender.

Whatever. He is Sherlock.

"You're my brother." He whispers fiercely.

Because that's the fucking truth that matters.

No matter the rest; Lestrade and Pack and Sherlock's gender identity and Mycroft's weird kinks, the truth remains.

The foundation of their worlds.

The rest will work itself out. Sherlock.

 _I love you_ , he mouths silently against the salty skin of Sherlock's back. His cock throbs, a deep twitch that seems to start in his spine. Sherlock's hole spasms in response.

Knotted.

 _I love you._ Mycroft thinks.

"Brother mine." He says out loud.

* * *

 _There have been several worried requests of "What about Greg?"_

 _Indeed, there is more to be written in this Verse. However, I am committed to a long story Arc in a different fandom. I might revisit these guys later, but for now it is firmly a one-shot._

 _Thank you for reading!_

 _Xxx_

 _FrenchCaresse_


End file.
